JP5663488B2 - Method and apparatus for supplying hydrogen selenide mixed gas for solar cell - Google Patents

Description

The present invention relates to an improvement in a method and apparatus for supplying a hydrogen selenide mixed gas for solar cells.
This application claims priority on October 14, 2009 based on Japanese Patent Application No. 2009-237154 for which it applied to Japan, and uses the content here.

  In recent years, solar cells have been attracting attention as an alternative energy to petroleum due to problems such as environmental pollution, global warming, and fossil fuel depletion. As a CIGS (Cu (InGa) Se) -based thin film solar cell which is the current mainstream of solar cells, for example, the compound solar cell of Patent Document 1 is known.

Patent Document 1 discloses a chalcopyrite type light absorption layer containing copper, indium, gallium, and selenium and a method for manufacturing the same. Specifically, the chalcopyrite type light absorption layer thin film is formed by depositing copper (Cu), indium (In) and gallium (Ga) on a substrate by sputtering or the like, and then hydrogen selenide (H ₂ Se) gas. It is formed by annealing in the atmosphere.

By the way, when supplying a hydrogen selenide (H ₂ Se) mixed gas adjusted to a predetermined concentration in a compound solar cell manufacturing apparatus, a mixed gas previously adjusted to a specified concentration has been used. However, in response to the recent increase in demand for solar cells, it has been necessary to supply a large amount of hydrogen selenide mixed gas to the solar cell manufacturing apparatus in order to realize mass production of compound solar cells. For this reason, if a gas cylinder filled with a mixed gas adjusted to a specified concentration is used, there is a problem that the replacement frequency of the cylinder increases, and a sufficient gas supply amount cannot be secured.

  Therefore, as shown in FIG. 3, a hydrogen selenide mixed gas supply apparatus 101 capable of continuously supplying a hydrogen selenide mixed gas is used. The supply device 101 is provided with a base gas supply flow path L101 connected to a base gas supply source (not shown) and a source gas supply flow path L102 connected to a source gas supply source (not shown). In each case, an inert gas and a hydrogen selenide gas having a concentration of 100% can be supplied. The base gas supply channel L101 and the source gas supply channel L102 are respectively provided with mass flow controllers (MFC) 105 and 112 capable of controlling the flow rate. A buffer tank 102 for storing a hydrogen selenide mixed gas adjusted to a predetermined concentration is provided downstream of the base gas supply channel L101 and the source gas supply channel L102.

  In the conventional hydrogen selenide mixed gas supply method using the supply device 101, first, the flow rates of the mass flow controllers 105 and 112 provided in the base gas supply flow path L101 and the source gas supply flow path L102 are set to a predetermined value. Set the flow rate ratio. Next, in the subsequent stage of the mass flow controllers 105 and 112 set to constant flow rates, 100% hydrogen selenide gas and base gas are mixed with a mixer to adjust to a predetermined concentration, and the resulting selenization for solar cells is performed. The hydrogen mixed gas is stored in the buffer tank 102. And this hydrogen selenide mixed gas for solar cells was supplied from the buffer tank 102 to the solar cell manufacturing apparatus. The mass flow controller 112 for controlling the flow rate of 100% hydrogen selenide gas provided in the source gas supply flow path L102 detects the thermal diffusion due to the inflow gas by a flow rate sensor and adjusts the flow rate.

JP 2007-317885 A

However, in the conventional supply apparatus and supply method, when high-concentration hydrogen selenide gas is passed through the source gas supply pipe L102 and the mass flow controller 112 for a long time, hydrogen selenide (H ₂ Se) becomes hydrogen (H ₂ ) and selenium. As a result of the self-decomposition into (Se), a selenium crystal was precipitated on the flow rate sensors inside the source gas supply pipe L102 and the source gas mass flow controller 112. Due to this phenomenon, there is a problem that the flow rate control is not effective. As described above, when the flow rate control is lost, the mass flow controller (MFC) 112 for 100% hydrogen selenide gas determines that a smaller amount of gas is flowing than the actual flow and opens the control valve. A larger amount of gas will flow. As a result, with the passage of time from the start of supply of the hydrogen selenide gas mixture, the concentration of the target hydrogen selenide gas mixture (setting value) and the concentration of the hydrogen selenide gas mixture actually prepared (measured value) There is a problem that the error between the two becomes large (this is called a drift phenomenon (see FIG. 4)).

  The present invention has been made in view of the above circumstances, and a method for supplying a hydrogen selenide mixed gas for solar cells capable of continuously supplying a hydrogen selenide mixed gas having a stable hydrogen selenide concentration. And it aims at providing a supply apparatus.

To solve this problem,
The first aspect of the present invention is adjusted to a predetermined concentration by mixing an inert gas supplied from a base gas supply channel and 100% hydrogen selenide gas supplied from a source gas supply channel. A method for supplying a hydrogen selenide mixed gas for solar cells, comprising the step of supplying a hydrogen selenide mixed gas,
The base gas supply channel and the source gas supply channel are provided with a bypass channel communicating with each other,
After deriving a predetermined amount of the 100% hydrogen selenide gas from the source gas supply channel, the inert gas is derived from the source gas supply channel via the bypass channel to obtain a predetermined concentration of selenium. This is a method for supplying a hydrogen selenide mixed gas for solar cells, in which a hydrogen halide mixed gas is prepared and the volume concentration of hydrogen selenide remaining in the raw material gas supply channel is 10% or less.

In the first aspect of the present invention, flow path blocking means are provided on the upstream side and the downstream side of the source gas supply flow path, respectively.
It is preferable that the volume concentration of hydrogen selenide in the source gas supply channel sealed by the upstream and downstream channel blocking means is 10% or less.

Further, in the first aspect of the present invention, the supplying step derives a predetermined amount of the inert gas from the base gas supply flow path and uses a predetermined amount of the 100% hydrogen selenide gas as the raw material. A first step derived from the gas supply flow path;
A second step of deriving a predetermined additional amount of the 100% hydrogen selenide gas from the source gas supply flow path;
And a third step of deriving a predetermined additional amount of the inert gas from the source gas supply flow path via the bypass path in accordance with the predetermined additional amount of the 100% hydrogen selenide gas. It is preferable.

In the first aspect of the present invention, a mixed gas storage tank is provided on the downstream side of the base gas supply channel and the source gas supply channel,
All of the inert gas and 100% hydrogen selenide gas derived in the first to third steps are supplied to the mixed gas storage tank, and the selenization in the hydrogen selenide mixed gas in the mixed gas storage tank is performed. It is preferable to adjust the volume concentration of hydrogen to a predetermined concentration.

A second aspect of the present invention includes a base gas supply channel,
A source gas supply channel;
A bypass channel provided to communicate the base gas supply channel and the source gas supply channel;
Channel blocking means provided on the upstream side and downstream side of the source gas supply channel, respectively,
The bypass channel is connected to the upstream channel shutoff unit side between the upstream channel shutoff unit and the downstream channel shutoff unit of the source gas supply channel,
Supplying a hydrogen selenide mixed gas adjusted to a predetermined concentration by mixing an inert gas supplied from the base gas supply channel and a 100% hydrogen selenide gas supplied from the source gas supply channel It is a supply apparatus of the hydrogen selenide mixed gas for solar cells.

In the second aspect of the present invention, the source gas supply flow path is provided with a flow rate control means for controlling the flow rate of the 100% hydrogen selenide gas,
It is preferable that the flow rate control means is disposed between the upstream flow path blocking means and the downstream flow path blocking means.

  Further, the second aspect of the present invention is a mixed gas storage tank provided on the downstream side of the base gas supply channel and the source gas supply channel, and a hydrogen selenide mixture stored in the mixed gas storage tank. It is preferable to further include a gas concentration analyzer that measures the hydrogen selenide concentration in the gas.

  According to the method for supplying a hydrogen selenide mixed gas for a solar cell of the present invention, after deriving 100% hydrogen selenide gas from the source gas supply channel, the inert gas is supplied from the source gas supply channel via the bypass channel. Thus, a hydrogen selenide mixed gas having a predetermined concentration is prepared, and control is performed so that the volume concentration of hydrogen selenide remaining in the source gas supply channel is 10% or less. This suppresses the self-decomposition of hydrogen selenide and reduces the precipitation of selenium crystals into the raw material gas supply flow path, thus enabling a stable supply of 100% hydrogen selenide gas and the concentration of hydrogen selenide. However, a stable hydrogen selenide mixed gas can be continuously supplied.

  Also, a first step of deriving a predetermined amount of inert gas and 100% hydrogen selenide gas from the respective supply channels, and deriving a predetermined additional amount of 100% hydrogen selenide gas from the source gas supply channel. In the case of including the second step and the third step of deriving an inert gas in an amount corresponding to the additional amount of 100% hydrogen selenide gas from the source gas supply flow path via the bypass path, In the step and the third step, the amount ratio of the additional inert gas derived from the source gas supply path and the 100% hydrogen selenide gas can be easily adjusted to a predetermined value. Thereby, the hydrogen selenide mixed gas in which the mixing ratio of the inert gas and the 100% hydrogen selenide gas is always kept constant (that is, the hydrogen selenide concentration is stable) can be continuously supplied. . Therefore, the error between the set value of the hydrogen selenide concentration in the hydrogen selenide gas mixture and the measured value can always be kept small, and as a result, the drift phenomenon of the hydrogen selenide concentration in the hydrogen selenide gas mixture can be suppressed. Can do.

  Further, a mixed gas storage tank is provided on the downstream side of the base gas supply channel and the source gas supply channel, and all of the inert gas and 100% hydrogen selenide gas derived from each supply channel are mixed. When supplying to a storage tank, all can be made into product gas (hydrogen selenide mixed gas), without discarding base gas and source gas.

  The apparatus for supplying a hydrogen selenide mixed gas for solar cell according to the present invention is provided so as to communicate a base gas supply channel, a source gas supply channel, a base gas supply channel, and a source gas supply channel. Therefore, the inert gas can be led out from the base gas supply channel to the source gas supply channel via the bypass channel. As a result, the inside of the source gas supply channel can be replaced with an inert gas, and the concentration of hydrogen selenide in the pipe of the source gas supply channel during sealing that is not being vented can be reduced. Further, a flow path blocking means is provided on each of the upstream side and the downstream side of the raw material gas supply flow path, and the bypass flow path is provided on the upstream side of the raw material gas supply flow path and on the downstream side. It is possible to seal the inside of the source gas supply flow path because it is connected to the upstream side flow path blocking means side. As a result, the gas mainly composed of the inert gas can be sealed in the sealed flow path of the source gas supply flow path.

It is a schematic diagram which shows the supply apparatus of the hydrogen selenide mixed gas for solar cells which is one Embodiment of this invention. It is a figure for demonstrating the Example of this invention, Comprising: It is a graph which shows the density | concentration change of the mixed gas at the time of supplying hydrogen selenide mixed gas continuously. It is a schematic diagram which shows the supply apparatus of the conventional hydrogen selenide mixed gas for solar cells. It is a figure which shows the relationship between the setting value of the hydrogen selenide gas density | concentration in the mixed gas in the conventional supply method of the hydrogen selenide mixed gas for solar cells, and a measured value.

DESCRIPTION OF EMBODIMENTS Hereinafter, a method for supplying a hydrogen selenide mixed gas for solar cells, which is an embodiment to which the present invention is applied, will be described in detail with reference to the drawings, together with a device for supplying a hydrogen selenide mixed gas for solar cells.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.
As for the units used in this specification, the concentration represents volume concentration, the pressure represents gauge pressure, and the flow rate represents volume flow rate. Furthermore, the volume shown in this specification is a volume in a reference state (0 ° C., 1 atm (atmospheric pressure)).

First, a configuration of a hydrogen selenide mixed gas supply device for solar cells (hereinafter simply referred to as “supply device”), which is an embodiment to which the present invention is applied, will be described.
As shown in FIG. 1, the supply apparatus 1 of this embodiment is an apparatus which supplies the hydrogen selenide mixed gas adjusted to the predetermined density | concentration according to the production condition in the manufacturing apparatus of a solar cell. Specifically, the supply device 1 includes a base gas supply channel L1 for supplying a base gas, a source gas supply channel L2 for supplying a source gas, the base gas supply channel L1, and the source material. A bypass flow path L7 provided to communicate with the gas supply flow path L2, and a buffer tank (mixed gas storage tank) 2 for storing the hydrogen selenide mixed gas adjusted to a predetermined concentration. It is roughly structured.

One end of the base gas supply flow path L1 is connected to a base gas supply source (not shown), and the other end is connected to a mixer (not shown).
The base gas is not particularly limited as long as it is an inert gas for dilution use. Examples of the gas include nitrogen (N ₂ ) gas, argon (Ar) gas, and the like.

  In the base gas supply flow path L1, an opening / closing valve 3, a pressure regulator 4, a mass flow controller (MFC) 5, and an automatic valve 6 are sequentially provided from the upstream side to the downstream side. Pressure gauges 7 and 8 are provided on the upstream side and the downstream side of the pressure regulator 4, respectively, so that the pressure before and after the pressure regulator 4 can be visually recognized.

The pressure regulator 4 is provided to reduce the pressure of the base gas supplied from the base gas supply source to a desired pressure. In the supply apparatus 1 of the present embodiment, only one pressure regulator 4 is shown in the base gas supply flow path L1, but the present invention is not limited to this, and two or more pressure regulators 4 are provided. May be.
Note that the pressure immediately before the mass flow controller 5 can be appropriately selected according to the supply pressure to the solar cell manufacturing apparatus. For example, the pressure immediately before the mass flow controller 5 can be in the range of 0.6 to 0.7 MPa.

  The mass flow controller 5 is a flow rate control device that controls the flow rate by measuring the mass flow rate of the base gas, and can perform high-precision flow rate measurement and control. The mass flow sensor mounted on the mass flow controller 5 is not particularly limited, and a general one such as a thermal mass flow sensor or a differential pressure mass flow sensor can be used.

The source gas supply channel L2 has one end connected to a source gas supply source (not shown) and the other end connected to a mixer (not shown).
The source gas is hydrogen selenide (H ₂ Se) gas having a concentration of 100%. In the present specification, it is simply referred to as 100% hydrogen selenide gas.

  In the source gas supply flow path L2, from the upstream side toward the downstream side, an automatic valve (upstream flow path blocking means) 9, an open / close valve 10, a pressure regulator 11, a mass flow controller (flow rate control means) 12, automatic A valve (downstream channel blocking means) 14 is sequentially provided. Pressure gauges 15 and 16 are provided on the upstream side and the downstream side of the pressure regulator 11, respectively, so that the pressure before and after the pressure regulator 11 can be visually recognized.

  The pressure regulator 11 is provided to reduce the pressure of 100% hydrogen selenide gas supplied from the source gas supply source to a desired pressure. In the supply apparatus 1 of the present embodiment, only one pressure regulator 11 is shown in the raw material gas supply flow path L2, but this is not a limitation, and two or more pressure regulators 11 are provided. May be.

  The mass flow controller (MFC) 12 controls the flow rate of 100% hydrogen selenide gas in the raw material gas supply flow path L2, and the automatic valve 9 disposed on the upstream side in the raw material gas supply flow path L2 and the downstream side. It is provided between the arranged automatic valves 14. Here, the mass flow controller 12 is a flow control device that controls the flow rate by measuring the mass flow rate of the raw material gas, and can perform high-precision flow rate measurement and control. The mass flow sensor mounted on the mass flow controller 12 is not particularly limited, and a general one such as a thermal mass flow sensor or a differential pressure mass flow sensor can be used.

  The mixer (not shown) to which the base gas supply channel L1 and the source gas supply channel L2 are connected and the buffer tank 2 are connected by a channel L3. Open / close valves 17 and 18 are provided on the upstream side and the downstream side of the flow path L3, respectively.

  The buffer tank 2 is a storage tank for storing the hydrogen selenide mixed gas adjusted to a predetermined concentration by the mixer. The buffer tank 2 is provided on the downstream side of the base gas supply channel L1 and the source gas supply channel L2. Moreover, the capacity | capacitance of the buffer tank 2 is not specifically limited, According to the supply amount of the hydrogen selenide mixed gas to a solar cell manufacturing apparatus, it can select suitably.

  The buffer tank 2 is provided with a supply port (not shown). One end of the flow path L4 is connected to the supply port, and the other end of the flow path L4 is connected to the solar cell manufacturing apparatus. . Thereby, the hydrogen selenide mixed gas can be supplied from the buffer tank 2 to the solar cell manufacturing apparatus. An opening / closing valve 19 is provided on the supply port side of the flow path L4.

  Further, one end of a flow path L5 is connected to the buffer tank 2, and the other end of the flow path L5 is connected to the pressure gauge 20. With the pressure gauge 20, the pressure in the buffer tank can be confirmed. An opening / closing valve 21 is provided in the flow path L5.

  Further, the buffer tank 2 communicates with a flow path L6 branched from the flow path L3. The flow path L6 has one end connected to the flow path L3 and the other end connected to an exhaust duct (not shown). A gas concentration analyzer 22 is provided in the flow path L6. This gas concentration analyzer 22 can measure the hydrogen selenide concentration in the hydrogen selenide mixed gas stored in the buffer tank 2. In addition, on the upstream side and the downstream side of the gas concentration analyzer 22, open / close valves 23 and 24 are provided, respectively.

  The bypass flow path L7 is a flow path provided for supplying an inert gas from the base gas supply flow path L1 to the source gas supply flow path L2. As shown in FIG. 1, one end of the bypass flow path L7 is connected to the upstream side of the on-off valve 3 in the base gas supply flow path L1. Further, the other end of the bypass flow path L7 is between the upstream automatic valve 9 and the downstream automatic valve 14 of the source gas supply flow path L2, and the upstream automatic valve 9 side (specifically, In the supply apparatus 1 of this embodiment, it is connected between the on-off valve 10 and the pressure regulator 11). Thereby, the base gas supply flow path L1 and the source gas supply flow path L2 are communicated, and the inert gas can be supplied from the base gas supply flow path L1 to the source gas supply flow path L2. Further, an automatic valve 25 is provided in the bypass flow path L7, and the flow path of the bypass flow path L7 can be freely opened and closed.

Next, a method for supplying the hydrogen selenide mixed gas for solar cells of the present embodiment using the supply device 1 (hereinafter simply referred to as “supply method”) will be described.
The supply method of the present embodiment has a predetermined concentration by mixing the inert gas supplied from the base gas supply flow path L1 and the 100% hydrogen selenide gas supplied from the source gas supply flow path L2. It is the supply method of the hydrogen selenide mixed gas for solar cells which has the process of supplying the adjusted hydrogen selenide mixed gas. Then, after deriving a predetermined amount of 100% hydrogen selenide gas from the raw material gas supply flow path L2, an inert gas is derived from the raw material gas supply flow path L2 via the bypass flow path L7, and a predetermined concentration is obtained. The hydrogen selenide mixed gas is prepared, and the volume concentration of hydrogen selenide in the gas remaining in the raw material gas supply channel L2 is set to 10% or less.

  Specifically, in the supply method of the present embodiment, an upper limit value and a lower limit value are set for the filling pressure of the hydrogen selenide mixed gas having a predetermined concentration filled in the buffer tank 2, and the pressure in the buffer tank 2 is set. When the upper limit value or the lower limit value is reached, the badge system is used to start or stop the supply of the inert gas and 100% hydrogen selenide gas by the following first to third steps.

  First, supply preparation of the hydrogen selenide mixed gas for solar cells is performed. Specifically, in the supply device 1 shown in FIG. 1, the flow path is purged while opening and closing the open / close valves 3, 10, 17, 18, 19, 21, 23, 24. After completing the purge, all the open / close valves are opened, and all the automatic valves 6, 9, 14, 25 are closed to complete the supply preparation.

(First step)
In the first step, when the filling amount of the hydrogen selenide mixed gas in the mixed gas buffer tank 6 reaches the set lower limit value, a predetermined amount of inert gas is led out from the base gas supply flow path L1. By deriving a predetermined amount of 100% hydrogen selenide gas from the source gas supply flow path L2, a hydrogen selenide mixed gas having a predetermined concentration is supplied to the buffer tank 2.

  Specifically, first, when the pressure value of the pressure gauge 20 provided in the buffer tank 2 falls below the set lower limit value, the automatic valve 6 provided in the base gas supply flow path L1 and the source gas supply flow path L2 A supply start signal is transmitted to the provided automatic valves 9, 14, and the automatic valves 6, 9, 14 are opened. When these automatic valves 6, 9, and 14 are opened, an inert gas is supplied from a base gas supply source (not shown) to the base gas supply flow path L1, and 100% selenization is performed from a raw material gas supply source (not shown). Hydrogen gas is supplied to the source gas supply flow path L2. Next, the inert gas controlled to a predetermined flow rate by the mass flow controller 5 is led out from the base gas supply flow path L1, and 100% hydrogen selenide gas controlled to the predetermined flow rate by the mass flow controller 12 is the source gas. It is led out from the supply flow path L2 and introduced into a mixer (not shown). An inert gas and a 100% hydrogen selenide gas introduced into the mixer at a predetermined flow rate ratio are mixed to obtain a hydrogen selenide mixed gas having a predetermined concentration, and then to the buffer tank 2 via the flow path L3. Supplied.

Here, the concentration of hydrogen selenide in the hydrogen selenide mixed gas is not particularly limited, and can be appropriately selected according to the requirements of the solar electric manufacturing apparatus. Specifically, for example, the concentration of hydrogen selenide in the hydrogen selenide mixed gas can be 5 to 20 vol%.
The hydrogen selenide concentration in the hydrogen selenide mixed gas stored in the buffer tank 2 can be measured by the gas concentration analyzer 22.

(Second step)
In the second step, after the derivation of the predetermined amount of inert gas from the base gas supply channel L1 and the derivation of the predetermined amount of 100% hydrogen selenide gas from the source gas supply channel L2 are completed, An additional amount of 100% hydrogen selenide gas is further led out from the source gas supply flow path L2.

  Specifically, first, when the pressure value provided in the buffer tank 2 reaches the set upper limit value, the automatic valve 6 provided in the base gas supply flow path L1 and the automatic valve provided in the source gas supply flow path L2. A supply stop signal is transmitted to 9, 14 and these automatic valves 6, 9, 14 are closed. When these automatic valves 6, 9, and 14 are closed, the supply of the inert gas from the base gas supply source (not shown) to the base gas supply flow path L1 is stopped and the source gas is supplied from the source gas supply source (not shown). The supply of 100% hydrogen selenide gas to the supply flow path L2 is stopped. Thereby, the derivation of the inert gas from the base gas supply channel L1 and the derivation of the predetermined amount of 100% hydrogen selenide gas from the source gas supply channel L2 are completed.

  Next, a supply signal is transmitted to the automatic valves 9 and 14 provided in the source gas supply flow path L2, and the automatic valves 9 and 14 are opened for a predetermined time. During this time, a predetermined amount of 100% hydrogen selenide gas is further led out from the source gas supply flow path L2. The derived 100% hydrogen selenide gas is supplied to the buffer tank 2 through the flow path 3. Then, after a predetermined time has elapsed, the automatic valves 9 and 14 are closed. This completes the derivation of the predetermined additional amount of 100% hydrogen selenide gas from the source gas supply flow path L2.

  Here, in order to further supply a predetermined additional amount of 100% hydrogen selenide gas to the buffer tank 2, the hydrogen selenide concentration in the hydrogen selenide mixed gas stored in the buffer tank 2 in the first step is slightly To increase. Therefore, it is preferable to reduce the supply amount of 100% hydrogen selenide gas added in the second step as much as possible. The additional amount of 100% hydrogen selenide gas can be determined by appropriately adjusting the flow rate set by the mass flow controller 12 and the opening times of the automatic valves 9 and 14.

(Third step)
In the third step, a predetermined additional amount corresponding to the predetermined additional amount of the 100% hydrogen selenide gas after the derivation of the predetermined additional amount of 100% hydrogen selenide gas from the source gas supply flow path L2 is completed. The base gas is led out from the source gas supply flow path L2 via the bypass path L7.

  Specifically, first, when the automatic valves 9 and 14 are closed, a supply signal is transmitted to the automatic valve 25 provided in the bypass flow path L7 and the automatic valve 14 provided in the source gas supply flow path L2. The automatic valves 14 and 25 are opened for a predetermined time. During this time, a predetermined additional amount of inert gas is introduced from the base gas supply channel L1 to the source gas supply channel L2 via the bypass channel L2. Then, the inert gas derived from the source gas supply flow path L2 is supplied to the buffer tank 2 through the flow path 3. Next, after a predetermined time has elapsed, the automatic valves 14 and 25 are closed. Thereby, the derivation of the predetermined additional amount of the inert gas from the source gas supply flow path L2 is completed.

  In addition, since 100% hydrogen selenide gas is additionally supplied to the buffer tank 2 in the second step, the hydrogen selenide concentration in the hydrogen selenide mixed gas stored in the buffer tank 2 is the first step. There is a slight increase from the concentration adjusted in. Therefore, the supply amount of the inert gas added in the third step is 100 so that the concentration of hydrogen selenide in the hydrogen selenide mixed gas becomes the target concentration (that is, the concentration adjusted in the first step). It is preferable to adjust the supply amount according to the additional amount of% hydrogen selenide gas. The supply amount of the inert gas can be adjusted by appropriately changing the opening time of the automatic valve 14.

  By the way, in the third step, since the inert gas is supplied to the buffer tank 2 via the bypass path L7 and the raw material gas supply flow path L2, the inside of the raw material gas supply flow path L2 is completed when the third step is completed. That is, the inside of the flow path on the downstream side from the automatic valve 9 provided on the upstream side is replaced with the inert gas. After the completion of the third step, the automatic valve 9 provided on the upstream side of the raw material gas supply flow path L2, the automatic valve 14 provided on the downstream side, and the bypass flow path L7 branched from the raw material gas supply flow path L2. And the automatic valve 25 provided in is closed. For this reason, until the next first step is started, the mixed gas mainly containing an inert gas is sealed in the sealed source gas supply channel L2.

  Here, the above-mentioned mixed gas mainly containing an inert gas contains a slight amount of hydrogen selenide. The concentration of hydrogen selenide contained in this mixed gas is preferably 10% or less. If the concentration exceeds 10%, hydrogen selenide tends to self-decompose into hydrogen and selenium, and selenium crystals tend to precipitate in the source gas supply flow path L2, which is not preferable. On the other hand, since the self-decomposition of hydrogen selenide can be suppressed if the concentration is 10% or less, precipitation of selenium crystals into the source gas supply channel L2 can be effectively reduced. . Note that the pressure adjustment provided in the flow path sealed by the source gas supply flow path L2 (that is, the section between the automatic valve 9 provided on the upstream side and the automatic valve 14 provided on the downstream side). Precipitation of selenium crystals in the vessel 11 and the mass flow controller 12 can also be reduced. As a result, when a predetermined flow rate of inert gas and 100% hydrogen selenide gas are mixed and the hydrogen selenide mixed gas is adjusted to a predetermined concentration, 100% hydrogen selenide gas is supplied at a stable flow rate. be able to.

  The concentration of hydrogen selenide in the mixed gas is preferably as low as possible. However, when the aeration time and the aeration amount of the inert gas in the third step are increased, the concentration of hydrogen selenide in the mixed gas to be sealed is lowered. It is necessary to increase the aeration time and the aeration amount of% hydrogen selenide gas. Therefore, it should be noted that uneven density in the buffer tank 2 may occur.

  In the supply method of the present embodiment, since all of the additional inert gas and 100% hydrogen selenide gas derived from the source gas supply path L2 in the second step and the third step are supplied to the buffer tank 2, the base gas And all can be made into product gas (hydrogen selenide mixed gas), without discarding raw material gas. Moreover, the selenization stored in the buffer tank 2 by adjusting the quantity ratio of the additional inert gas and 100% hydrogen selenide gas derived from the source gas supply path L2 in the second step and the third step. The concentration of hydrogen selenide in the hydrogen mixed gas can be adjusted to a predetermined concentration.

The supply method of this embodiment is characterized by repeating the first step to the third step. By repeating the first to third steps in this manner, a hydrogen selenide mixed gas having a predetermined concentration can be prepared while the mixing ratio of the inert gas and the 100% hydrogen selenide gas is always kept constant. . Thereby, since the error between the set value of the hydrogen selenide concentration in the hydrogen selenide mixed gas and the measured value can always be kept small, the drift phenomenon of the hydrogen selenide concentration can be suppressed. In this way, a hydrogen selenide mixed gas having a stable hydrogen selenide concentration is continuously supplied to the solar cell manufacturing apparatus.
In the supply method of the present embodiment, the cycle from the first step to the third step is referred to as one badge.

  As described above, the hydrogen selenide mixed gas supply device 1 for the solar cell according to the present embodiment includes the base gas supply channel L1, the source gas supply channel L2, the base gas supply channel L1, and the source gas supply. Since the bypass flow path L7 is provided so as to communicate with the flow path L2, the inert gas is supplied from the base gas supply flow path L1 to the source gas supply flow path L2 via the bypass flow path L7. Can be derived. Thereby, the inside of the source gas supply flow path L2 can be replaced with the inert gas, and the hydrogen selenide concentration can be reduced. Further, automatic valves (flow path blocking means) 9 and 14 are provided on the upstream side and the downstream side of the source gas supply flow path L2, respectively, and the bypass flow path L7 is automatically connected to the upstream side of the source gas supply flow path L2. Since it is connected between the valve 9 and the downstream automatic valve 14 and is connected to the upstream automatic valve 14 side, the inside of the source gas supply flow path L2 can be sealed. As a result, a gas mainly composed of an inert gas can be sealed in the sealed flow path of the source gas supply flow path L2.

  Moreover, since the supply apparatus 1 of this embodiment is provided with the buffer tank 2, the hydrogen selenide mixed gas adjusted to the predetermined density | concentration can be stored. Thereby, hydrogen selenide mixed gas can be suitably supplied to a solar cell manufacturing apparatus according to the situation of production.

  The method for supplying the hydrogen selenide mixed gas for solar cell of the present embodiment is as follows. After the 100% hydrogen selenide gas is derived from the source gas supply channel L2, it is not supplied from the source gas supply channel L2 via the bypass channel L7. By deriving the active gas, a hydrogen selenide mixed gas having a predetermined concentration is prepared, and the volume concentration of hydrogen selenide remaining in the raw material gas supply channel is set to 10% or less. Thereby, the self-decomposition of hydrogen selenide is suppressed, and precipitation of selenium crystals into the raw material gas supply flow path is reduced, so that 100% hydrogen selenide gas can be stably supplied. Therefore, a hydrogen selenide mixed gas having a stable hydrogen selenide concentration can be continuously supplied to the solar cell manufacturing apparatus.

  Also, a first step for deriving a predetermined amount of inert gas and 100% hydrogen selenide gas from the respective supply flow paths L1, L2, and a source gas supply flow path for a predetermined additional amount of 100% hydrogen selenide gas A second step of deriving from L2, and a third step of deriving an amount of inert gas corresponding to the additional amount of 100% hydrogen selenide gas from the source gas supply flow path L2 via the bypass path L7. Therefore, it is possible to easily adjust the amount ratio of the additional inert gas and 100% hydrogen selenide gas derived from the source gas supply path L2 in the second step and the third step to a predetermined value. Thereby, the hydrogen selenide mixed gas in which the mixing ratio of the inert gas and the 100% hydrogen selenide gas is always kept constant (that is, the hydrogen selenide concentration is stabilized) is continuously supplied to the solar cell manufacturing apparatus. Can be supplied. Therefore, the error between the set value of the hydrogen selenide concentration in the hydrogen selenide gas mixture and the measured value can always be kept small, and as a result, the drift phenomenon of the hydrogen selenide concentration in the hydrogen selenide gas mixture can be suppressed. Can do.

  Further, since the buffer tank 2 is provided on the downstream side of the base gas supply channel L1 and the raw material gas supply channel L2, the inert gas and 100% hydrogen selenide gas derived from the supply channels L1 and L2 are provided. All of the above can be supplied to the buffer tank 2. Thereby, it can be set as all product gas (hydrogen selenide mixed gas), without discarding base gas and source gas.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the supply device 1 of the above embodiment, the flow rate of 100% hydrogen selenide gas is controlled using the mass flow controller 12 in the source gas supply flow path L2, but the flow rate of the 100% hydrogen selenide gas is changed. The structure is not particularly limited as long as it can be controlled. For example, instead of the mass flow controller 12, the flow rate may be controlled using flow control means such as an orifice or a needle valve that simply restricts the flow rate and pressure control means such as an automatic pressure control device (APR).

Specific examples are shown below.
(Test 1)
When supplying the hydrogen selenide mixed gas to the solar cell manufacturing apparatus using the supply device 1 shown in FIG. 1, the volume concentration of hydrogen selenide in the hydrogen selenide mixed gas in the buffer tank 2 is kept at 20%. The additional amount of 100% hydrogen selenide gas and the corresponding additional amount of inert gas were verified.
Moreover, the conditions of Table 1 were used as conditions for the supply device 1. In the supply device 1 shown in FIG. 1, an orifice having a diameter of 0.5 mm is installed at the inlets of the automatic valve 9 and the automatic valve 25, and the base gas flow rate when passing through the bypass path 7 is 6.28L. / Min.
In Test 1, unless otherwise specified, the pressure represents the gauge pressure, the flow rate represents the volume flow rate, and the volume represents the volume in the standard state (0 ° C., atmospheric pressure (1 atm = 101.3 kPa)).

First, the automatic valves 6, 9, and 14 are opened, and nitrogen (N ₂ ) gas as an inert gas is supplied from the base gas supply flow path L1, and 100% hydrogen selenide gas is supplied from the source gas supply flow path L2 to the buffer tank 2 respectively. Supplied. When the pressure in the buffer tank 2 reached the upper limit of 0.4 MPa, the automatic valves 6, 9, and 14 were closed (first step).

Next, the automatic valves 9 and 14 were opened for 2 seconds and then closed (second step). The 100% hydrogen selenide supplied to the buffer tank 2 in 2 seconds was 0.67 L as shown in the following formula (1).
2 (s) × 20 (L / min) × 1 (min) / 60 (s) = 0.67 (L) (1)

Next, the automatic valves 14 and 25 were opened for 25.6 seconds and then closed (third step).
Here, the amount X of nitrogen gas necessary for diluting 0.67 L of hydrogen selenide (H ₂ Se) to 20% was 2.68 L as shown in the following formulas (2) and (3). It was.
0.67 / (0.67 + X) = 0.2 (2)
X = (0.67− (0.2 × 0.67)) / 0.2 = 2.68 (L) (3)
Further, the time for opening the automatic valve 25 to supply 2.68 L of nitrogen gas was 25.6 seconds as shown in the following formula (4).
2.68 (L) / ((6.28 (L / min) × 1 (min) / 60 (s)) = 25.6 (s) (4)

After performing the said 1st-3rd step, when the volume concentration of the hydrogen selenide in the hydrogen selenide mixed gas in the buffer tank 2 was measured with the densitometer 22, it was confirmed that it is 20%.
In addition, since the volume of the buffer tank 2 is 200 L and the pressure of the buffer tank 2 after the completion of the first step is 0.4 MPa, the gas (hydrogen selenide + The volume of nitrogen) was 989.73 (L) as shown in the following formula (5) when converted to the volume in the standard state.
200 × (0.1013 + 0.4) /0.1013=989.73 (L) (5)
Further, since the hydrogen selenide mixed gas of hydrogen selenide 0.67 (L), nitrogen 2.68 (L), and total 3.35 (L) is additionally introduced by the second and third steps, the supply is completed. The pressure in the buffer tank 2 (after completion of the third step) was 0.402 MPa as shown in the following formula (6).
(0.1013 × (989.73 + 3.35) / 200) −0.1013 = 0.402 (6)
Furthermore, the dilution rate in the source gas supply flow path L2 after completion of supply (after completion of the third step) was 99% or more, and it was confirmed that the hydrogen selenide concentration was sufficiently reduced.

(Example 1)
The hydrogen selenide mixed gas was continuously supplied to the solar cell manufacturing apparatus using the supply apparatus 1 shown in FIG.
In addition, as the conditions of the supply device 1 when supplying the hydrogen selenide mixed gas, the conditions shown in Table 1 and the verification results of the test 1 were used.
Under the above operating conditions, when the hydrogen selenide mixed gas was continuously supplied to the solar cell manufacturing apparatus, the concentration change of the mixed gas was recorded using the gas concentration analyzer 22 connected to the buffer tank 2. The results are shown in FIG.

(Example 2)
The hydrogen selenide mixed gas was continuously supplied to the solar cell manufacturing apparatus using the supply apparatus 101 shown in FIG. The batch method using the buffer tank 102 was used for continuous supply of the hydrogen selenide mixed gas to the solar cell manufacturing apparatus, and the conditions shown in Table 1 were used as supply conditions for the hydrogen selenide mixed gas of the supply apparatus 101. .
Under the above operating conditions, when the hydrogen selenide mixed gas was continuously supplied to the solar cell manufacturing apparatus, the concentration change of the mixed gas was recorded using the gas concentration analyzer 122 connected to the buffer tank 102. The results are shown in FIG.

  As shown in FIG. 2, the measured concentration of the hydrogen selenide mixed gas in the buffer tank 102 in Example 2 which is the prior art fluctuated between 19% and 41% with respect to the set concentration of 20%. On the other hand, the measured concentration of the hydrogen selenide mixed gas in the buffer tank 2 in Example 1 to which the present invention is applied is suppressed to 19 to 21% with respect to the set concentration of 20%, and the fluctuation range of the concentration Was confirmed to be shrinking.

  Moreover, in Example 2 which is a prior art, it was confirmed that about 100 mg of selenium (Se) crystals were deposited on the piping which is the raw material gas supply flow path L102 and the sensor portion of the mass flow controller (MFC) 112. On the other hand, in Example 1 to which the present invention was applied, precipitation of selenium crystals could not be visually confirmed in the source gas supply flow path L2 and the mass flow controller 12.

1 ... Supply device (supply device for hydrogen selenide mixed gas for solar cells)
2 ... Buffer tank (mixed gas storage tank)
3, 10, 14, 17, 18, 19, 21, 21, 24 ... Open / close valve 4, 11 ... Pressure regulator 5, 12 ... Mass flow controller (flow rate control means)
6, 9, 14, 25 ... Automatic valve (flow path blocking means)
7, 8, 15, 16, 20 ... pressure gauge 22 ... gas concentration analyzer L1 ... base gas supply channel L2 ... source gas supply channel L3-L6 ... channel L7 ... bypass channel

Claims (7)

Supplying a hydrogen selenide mixed gas adjusted to a predetermined concentration by mixing an inert gas supplied from the base gas supply channel and a 100% hydrogen selenide gas supplied from the source gas supply channel A method for supplying a hydrogen selenide mixed gas for solar cells, comprising the steps of:
The base gas supply channel and the source gas supply channel are provided with a bypass channel communicating with each other,
After deriving a predetermined amount of the 100% hydrogen selenide gas from the source gas supply channel, the inert gas is derived from the source gas supply channel via the bypass channel to obtain a predetermined concentration. A method for supplying a hydrogen selenide mixed gas for solar cells, wherein a hydrogen selenide mixed gas is prepared and a volume concentration of hydrogen selenide remaining in the raw material gas supply flow path is 10% or less. Channel blocking means are provided on the upstream side and the downstream side of the source gas supply channel,
2. The hydrogen selenide mixed gas for solar cells according to claim 1, wherein the volume concentration of hydrogen selenide in the source gas supply flow path sealed by the flow path blocking means on the upstream side and the downstream side is 10% or less. Supply method. A first step of deriving a predetermined amount of the inert gas from the base gas supply channel and deriving a predetermined amount of the 100% hydrogen selenide gas from the source gas supply channel;
A second step of deriving a predetermined additional amount of the 100% hydrogen selenide gas from the source gas supply flow path;
And a third step of deriving a predetermined additional amount of the inert gas from the source gas supply flow path via the bypass path in accordance with the predetermined additional amount of the 100% hydrogen selenide gas. The supply method of the hydrogen selenide mixed gas for solar cells of Claim 1. On the downstream side of the base gas supply channel and the source gas supply channel, a mixed gas storage tank is provided,
All of the inert gas and 100% hydrogen selenide gas derived in the first to third steps are supplied to the mixed gas storage tank, and the selenization in the hydrogen selenide mixed gas in the mixed gas storage tank is performed. The method for supplying a hydrogen selenide mixed gas for solar cells according to claim 3 , wherein the volume concentration of hydrogen is adjusted to a predetermined concentration. A base gas supply channel;
A source gas supply channel;
A bypass channel provided to communicate the base gas supply channel and the source gas supply channel;
Channel blocking means provided on the upstream side and downstream side of the source gas supply channel, respectively,
The bypass channel is connected to the upstream channel shutoff unit side between the upstream channel shutoff unit and the downstream channel shutoff unit of the source gas supply channel,
Supplying a hydrogen selenide mixed gas adjusted to a predetermined concentration by mixing an inert gas supplied from the base gas supply channel and a 100% hydrogen selenide gas supplied from the source gas supply channel Supply device for mixed hydrogen selenide gas for solar cells. The source gas supply flow path is provided with a flow rate control means for controlling the flow rate of the 100% hydrogen selenide gas,
6. The apparatus for supplying a hydrogen selenide mixed gas for a solar cell according to claim 5, wherein the flow rate control means is disposed between the upstream-side flow path blocking means and the downstream-side flow path blocking means. A mixed gas storage tank provided downstream of the base gas supply channel and the source gas supply channel;
The apparatus for supplying a hydrogen selenide mixed gas for a solar cell according to claim 5, further comprising a gas concentration analyzer for measuring a hydrogen selenide concentration in the hydrogen selenide mixed gas stored in the mixed gas storage tank.

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