JP3364137B2 - Method for manufacturing silicon-based thin film photoelectric conversion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin film photoelectric conversion device, and more particularly to a cost reduction and performance improvement of a silicon-based thin film photoelectric conversion device. Note that in this specification, the terms “crystalline” and “microcrystalline” also include those partially including an amorphous state.

[0002]

2. Description of the Related Art A typical example of a thin film photoelectric conversion device is an amorphous silicon solar cell, and an amorphous photoelectric conversion material is usually formed by a plasma CVD method at a low film forming temperature of about 200 ° C. , Which can be formed on inexpensive substrates such as stainless steel and organic films, and is expected as a promising material for low-cost photoelectric conversion devices. Also, since amorphous silicon has a large absorption coefficient in the visible light region,
A short circuit current of 15 mA / cm ² or more has been realized in a solar cell using an amorphous photoelectric conversion layer having a thin film thickness of m or less.

However, amorphous silicon-based materials have a problem that photoelectric conversion characteristics are deteriorated by long-term light irradiation, as called the Stebler-Wronskey effect, and their effective sensitivity wavelength range is up to about 800 nm. Is. Therefore, in a photoelectric conversion device using an amorphous silicon-based material, there is a limit in reliability and high performance, and the original advantage that the degree of freedom in substrate selection and the low cost process can be used is not sufficient. Not alive.

On the other hand, in recent years, a photoelectric conversion device utilizing a thin film containing crystalline silicon such as polycrystalline silicon or microcrystalline silicon has been vigorously developed. These developments are attempts to achieve both low cost and high performance of a photoelectric conversion device by forming a good quality crystalline silicon thin film on an inexpensive substrate by a low temperature process. It is expected to be applied to various photoelectric conversion devices such as.

As a method for forming these crystalline silicon thin films, for example, CVD or sputtering is used to deposit directly on the substrate, or an amorphous film is once deposited by the same process and then thermal annealing or laser annealing is performed. There are methods such as crystallization by
In any case, it is necessary to perform the process at 550 ° C. or lower in order to use the inexpensive substrate as described above.

Among such processes, plasma C
The method of directly depositing a crystalline silicon thin film by the VD method is expected to be the easiest to lower the temperature of the process and to increase the area of the thin film, and is expected to obtain a high quality film by a relatively simple process. . When a polycrystalline silicon thin film is obtained by such a method, a high quality silicon thin film containing a crystalline material is once formed on a substrate by some process and then formed as a seed layer or a crystallization control layer. As a result, a good quality polycrystalline silicon thin film can be formed even at a relatively low temperature.

On the other hand, the silane source gas is diluted 10 times or more with hydrogen and the pressure in the plasma reaction chamber is set to 10 mTorr.
It is well known that a microcrystalline silicon thin film can be obtained by setting the film thickness within the range of 1 Torr by the plasma CVD method. In this case, the silicon thin film can be easily microcrystallized even at a temperature of about 200 ° C. Can be transformed. For example, a photoelectric conversion device including a photoelectric conversion unit composed of a pin junction of microcrystalline silicon is described in Appl, Phys, Lett., Vol 65,
1994, p.860. This photoelectric conversion unit is composed of a p-type semiconductor layer, an i-type semiconductor layer and an n-type semiconductor layer, which are photoelectric conversion layers, which are simply sequentially stacked by a plasma CVD method, and all of these semiconductor layers are microcrystalline silicon. Is characterized by. However, in order to obtain a high-quality crystalline silicon film and further a high-performance silicon-based thin film photoelectric conversion device, the film formation rate is less than 10 nm / min in the thickness direction under the conventional manufacturing method and conditions. It is as slow as it is, and is as low as or less than that of the amorphous silicon film.

On the other hand, an example in which a silicon film is formed by a low temperature plasma CVD method under a relatively high pressure condition of 5 Torr is described in JP-A-4-137725. However, this example is a case where a silicon thin film is directly deposited on a substrate such as glass, which is a comparative example with respect to the invention disclosed in Japanese Patent Laid-Open No. 4-137725. It cannot be applied.

Generally, if the pressure condition of the plasma CVD method is raised, a large amount of powdery products and dusts are generated in the plasma reaction chamber. In that case, there is a high risk that those dusts and the like fly to the surface of the film being deposited and are taken into the deposited film, which causes pinholes in the film. Then, in order to reduce such deterioration of the film quality, it is necessary to frequently clean the reaction chamber. In particular, when a film is formed under a low temperature condition such as 550 ° C. or less, these problems become remarkable when the reaction chamber pressure is increased. Moreover, in manufacturing a photoelectric conversion device such as a solar cell, it is necessary to deposit a large-area thin film, which causes serious problems such as a decrease in product yield and an increase in labor and cost for maintaining the film forming device. .

Therefore, when the thin film photoelectric conversion device is manufactured by using the plasma CVD method, the pressure condition of 1 Torr or less is conventionally used as described above.

[0011]

The photoelectric conversion device including the crystalline silicon-based thin film photoelectric conversion layer as described above has the following problems. In other words, whether it is polycrystalline silicon or microcrystalline silicon partially containing an amorphous phase , when it is used as a photoelectric conversion layer of a solar cell, considering the absorption coefficient of crystalline silicon, it absorbs sunlight sufficiently. To achieve this, a film thickness of at least several μm to several tens of μm is required. This is one to two orders of magnitude thicker than that of the amorphous silicon photoelectric conversion layer.

However, according to the conventional techniques, in order to obtain a good quality crystalline silicon thin film at a low temperature by the plasma CVD method, various factors such as temperature, pressure in the reaction chamber, high frequency power, and gas flow rate ratio are used. Examination of the film forming condition parameters revealed that the film forming rate was about the same as or lower than that of the amorphous silicon film, for example, only about 10 nm / min. In other words, the crystalline silicon thin film photoelectric conversion layer requires a film formation time which is many times to several tens of times longer than that of the amorphous silicon photoelectric conversion layer, which makes it difficult to improve the throughput of the manufacturing process of the photoelectric conversion device. Thus hindering cost reduction.

In view of the above problems of the prior art, an object of the present invention is to improve the throughput of the manufacturing process by increasing the film formation rate of the crystalline silicon photoelectric conversion layer formed by the low temperature plasma CVD method. And to improve the performance of the photoelectric conversion device.

[0014]

In the method for manufacturing a silicon-based thin film photoelectric conversion device according to the present invention, the photoelectric conversion device includes at least one photoelectric conversion unit formed on a substrate, and the photoelectric conversion unit has a high frequency. A semiconductor layer of one conductivity type sequentially stacked by a plasma CVD method,
A silicon-based film photoelectric conversion layer containing a crystalline material and an opposite conductivity type semiconductor layer are included, and the photoelectric conversion layer is a plasma CV.
As conditions for depositing by the D method: the base temperature is 550 ° C. or lower; the silane-based gas and the hydrogen gas are included as the main components of the gas introduced into the plasma reaction chamber, and the flow rate of the hydrogen gas is 50 times the silane-based gas There above; plasma reaction pressure in the chamber is set to more than 3 Torr; RF and
0.05W / cm ² or more at frequencies below 150MHz to
Power above is applied; element, deposited in the thickness direction 16 nm / min or faster to a thickness in the range of 0.5~20μm
As a result, the photoelectric conversion layer becomes a polycrystalline silicon film.
Or a microcrystalline silicon film with a volume crystallization fraction of 80% or more
And at least 0.5 atomic% and less than 30 atomic% hydrogen
It is characterized in that it is formed as containing .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic perspective view illustrating a silicon-based thin film photoelectric conversion device manufactured according to one embodiment of the present invention. A metal such as stainless steel, an organic film, an inexpensive glass having a low melting point, or the like can be used for the substrate 201 of this device.

The back electrode 210 on the substrate 201 includes one or more of the following thin films (A) and (B), and can be formed by, for example, a vapor deposition method or a sputtering method. (A) Ti, Cr, Al, Ag, Au, Cu and P
A metal thin film comprising at least one metal selected from t or alloys thereof. (B) A transparent conductive thin film made of at least one oxide selected from ITO, SnO ₂ and ZnO.

The photoelectric conversion unit 2 is provided on the back electrode 210.
One of the 11 semiconductor layers 204 of one conductivity type is deposited by the plasma CVD method. As the 1-conductivity type semiconductor layer 204, for example, phosphorus which is a conductivity-type determining impurity atom is 0.0
An n-type silicon layer doped with 1 atomic% or more, a p-type silicon layer doped with 0.01 atomic% or more of boron, or the like can be used. However, these conditions for the one-conductivity-type semiconductor layer 204 are not limited, and the impurity atom may be, for example, aluminum or the like in the p-type silicon layer, or an alloy material such as silicon carbide or silicon germanium. Good. The conductive type silicon-based thin film 204 may be polycrystalline, microcrystalline, or amorphous, and its film thickness is set within the range of 1 to 100 nm, more preferably within the range of 2 to 30 nm.

The photoelectric conversion layer 205 of a silicon-based thin film containing a crystalline material is a non-doped i-type polycrystalline silicon thin film, an i-type microcrystalline silicon thin film having a volume crystallization fraction of 80% or more, or a weak impurity containing a trace amount of impurities. p-type or silicon-based thin film material is provided with sufficient photoelectric conversion function with a weak n-type that could be used. The film thickness of the photoelectric conversion layer 205 is 0.5 to 20
It is in the range of μm and has a film thickness necessary and sufficient for a crystalline silicon thin film photoelectric conversion layer.

The crystalline silicon-based photoelectric conversion layer 205 can be formed by a parallel plate type RF plasma CVD method which is widely used in general, and a high frequency power source from RF band to VHF band with a frequency of 150 MHz or less. May be performed by a plasma CVD method using.

The film formation temperature of the crystalline silicon type photoelectric conversion layer 205 in these plasma CVD methods is 550 ° C. or lower at which the above-mentioned inexpensive substrate can be used.

Crystalline silicon-based thin film photoelectric conversion layer 205
Has a reaction chamber pressure of 3 Torr in the plasma CVD method.
It is deposited under a condition of not less than r, more preferably not less than 5 Torr. The high frequency power density at that time is 20 m.
W / cm ² or more, preferably 50 mW / cm
It is more preferably ² or more. Furthermore, the main components of the gas introduced into the reaction chamber include silane-based gas and hydrogen gas, and the flow rate of hydrogen gas with respect to the silane-based gas is 5
It is made 0 times or more. Monosilane as the silane-based gas,
Disilane and the like are preferable, but in addition to these, a silicon halide gas such as silicon tetrafluoride, silicon tetrachloride, and dichlorosilane may be used. In addition to these, an inert gas such as a rare gas, preferably helium, neon, argon or the like may be used.

The present invention is characterized in that the film formation rate can be set to 16 nm / min or more under the above-mentioned formation conditions of the crystalline silicon-based photoelectric conversion layer 205.

This crystalline silicon-based thin film photoelectric conversion layer 20
Most of the crystal grains contained in No. 5 grow in a columnar shape extending upward from the underlayer 204. Many of these crystal grains have a (110) preferred crystallographic orientation plane parallel to the film plane, and
(11) for the (220) diffraction peak obtained by line diffraction
1) The intensity ratio of diffraction peaks is preferably 1/10 or less, and more preferably 1/20 or less. Even when the surface shape of the one-conductivity-type layer 204, which is the underlayer, is substantially flat, the surface after the formation of the photoelectric conversion layer 205 has minute intervals smaller than the film thickness by about one digit. A surface texture structure having irregularities is formed.

Further, the obtained crystalline silicon type thin film 20.
5, the hydrogen content determined by secondary ion mass spectrometry is preferably in the range of 0.5 atom% or more and 30 atom% or less, and preferably in the range of 1 atom% or more and 20 atom% or less. Is more preferable.

In the method of forming the crystalline silicon type thin film photoelectric conversion layer 205 of the present invention, since the pressure is higher than the conventional pressure condition of less than 3 Torr, ion damage in the film can be reduced as much as possible. Therefore, even if the high frequency power is increased or the gas flow rate is increased in order to increase the film formation speed, the ion damage on the surface of the deposited film is small and a good quality film can be formed at a high speed. Also, if film formation is performed under high pressure conditions, contamination due to powder formation in the reaction chamber may occur, but since the raw material gas is diluted with a large amount of highly thermally conductive gas such as hydrogen, this problem also occurs. Hateful.

Further, for the following reasons, the present invention can provide a crystalline silicon-based thin film 205 of higher quality than in the conventional method. First, since the film forming rate is high, the ratio of the impurity atoms such as oxygen and nitrogen remaining in the reaction chamber taken into the film is reduced. Further, since the crystal nucleation time in the initial stage of film growth is short, the nucleation density is relatively reduced, and crystal grains having a large grain size and strongly crystallized are likely to be formed. Furthermore, if the film is formed at a high pressure, defects in crystal grain boundaries and grains are likely to be passivated by hydrogen, and the defect density of those defects is also reduced.

The underlying layer 20 is formed on the photoelectric conversion layer 205.
A silicon type thin film as a conductivity type semiconductor layer 206 of the opposite type to that of No. 4 is deposited by the plasma CVD method. The reverse conductivity type silicon-based thin film 206 is, for example, a p-type silicon thin film doped with 0.01 atom% or more of boron, which is a conductivity determining impurity atom, or an n-type silicon doped with 0.01 atom% or more of phosphorus. Thin films and the like can be used. However, these conditions for the opposite conductivity type semiconductor layer 206 are not limited, and aluminum or the like may be used as the impurity atom in p-type silicon, and a film of an alloy material such as silicon carbide or silicon germanium is used. May be. The reverse conductivity type silicon-based thin film 206 may be polycrystalline, microcrystalline, or amorphous, and its film thickness is set within the range of 3 to 100 nm, more preferably within the range of 5 to 50 nm. .

On the photoelectric conversion unit 111, ITO,
A transparent conductive oxide film 207 composed of at least one layer selected from SnO ₂ , ZnO, etc. is formed, and Al, Ag, Au, Cu, and
A comb-shaped metal electrode 208 including a layer of at least one metal selected from Pt or the like or an alloy thereof is formed by a sputtering method or a vapor deposition method, whereby a photoelectric conversion device as shown in FIG. 1 is obtained. Complete.

FIG. 2 is a schematic perspective view illustrating a tandem type silicon-based thin film photoelectric conversion device manufactured according to another embodiment of the present invention. In the tandem photoelectric conversion device of FIG. 2, the substrate 40 is used as in the case of FIG.
1 to the plurality of layers 402 to 406 are similarly formed corresponding to the plurality of layers 202 to 206 on the substrate 201 of FIG.

However, in the tandem type photoelectric conversion device of FIG. 2, it is stacked on the first photoelectric conversion unit 411,
The second photoelectric conversion unit 412 is further formed by the plasma CVD method. The second photoelectric conversion unit 412 is
The first photoelectric conversion unit 411 is sequentially laminated on the first photoelectric conversion unit 411.
Conductive microcrystal or amorphous silicon-based thin film 4
13, an amorphous silicon-based thin film photoelectric conversion layer 414 that is substantially an intrinsic semiconductor, and a microcrystalline or amorphous silicon-based thin film 415 of the opposite conductivity type.

A front transparent electrode 407 and a comb-shaped metal electrode 408 are formed on the second photoelectric conversion unit 412 in the same manner as the corresponding elements 207 and 208 in FIG.
As a result, the tandem photoelectric conversion device of FIG. 2 is completed.

As still another embodiment of the present invention, a tandem type silicon-based thin film photoelectric conversion device of the light incident type on the glass substrate side as shown in FIG. 3 can be manufactured. In the photoelectric conversion device of FIG. 3, first, the layer 6 corresponding to the transparent conductive layer 407 in FIG. 2 is formed on the transparent substrate 601.
07 is formed. Then, on the transparent conductive layer 607, a plurality of layers 402 to 406 and 413 to 415 in FIG.
To a plurality of layers 602-606 and 613-
615 is deposited with the stacking order reversed. At this time, the layers 602 to 607 and 613 to 615 in FIG. 3 can be formed similarly according to the corresponding layers 402 to 407 and 413 to 415 in FIG.

In the series of manufacturing steps of the silicon-based thin film photoelectric conversion device described above, the biggest problem in the past in improving throughput is a crystalline photoelectric conversion layer requiring a large film thickness. (205,405,60
It goes without saying that it was the manufacturing process of 5). However, according to the present invention, the film formation speed of the crystalline photoelectric conversion layer is significantly improved, and a film of higher quality can be obtained. Therefore, high performance and low cost of the silicon-based thin film photoelectric conversion device are achieved. Can greatly contribute to.

[0034]

EXAMPLES Hereinafter, silicon-based thin film solar cells as silicon-based thin film photoelectric conversion devices according to some examples of the present invention will be described together with solar cells according to comparative examples.

Example 1 A crystalline silicon thin film solar cell as Example 1 was produced corresponding to the embodiment shown in FIG. First, the back electrode 210 is formed on the glass substrate 201.
As a result, the Ag film 202 having a thickness of 300 nm and the ZnO film 203 having a thickness of 100 nm thereon were each formed by the sputtering method. On the back electrode 210, a 30-nm-thick phosphorus-doped n-type microcrystalline silicon layer 20 is formed.
4, a non-doped polycrystalline silicon thin film photoelectric conversion layer 205 having a thickness of 3 μm, and a boron-doped p-type microcrystalline silicon layer 206 having a thickness of 15 nm are respectively formed by the RF plasma CVD method, and the nip photoelectric conversion unit 21 is formed.
1 was formed. On the photoelectric conversion unit 211, a transparent conductive ITO film having a thickness of 80 nm was deposited as a front electrode 207 by a sputtering method, and a comb-shaped Ag electrode 208 for extracting a current was deposited thereon by an evaporation method. .

The polycrystalline silicon thin film photoelectric conversion layer 205 is
RF plasma C using a 13.56 MHz high frequency power supply
It was deposited by the VD method. In the reaction gas used at that time, the flow ratio of silane and hydrogen was mixed at 1:60, and the pressure in the reaction chamber was set to 3.0 Torr. The discharge power density is 80 mW / cm ² , and the film formation temperature is 400
Was set to ° C. Under such film forming conditions, the film forming rate of the polycrystalline silicon thin film photoelectric conversion layer 205 is 16 nm /
It was a minute. Further, with respect to the (220) diffraction peak obtained by X-ray diffraction for this photoelectric conversion layer 205, (111)
The intensity ratio of diffraction peaks was 1/16, and the hydrogen content determined by secondary ion mass spectrometry was 0.8 atom%.

As the incident light 209, AM1.5 light of 100 mW / is incident on the polycrystalline silicon thin film solar cell of the first embodiment.
With respect to the output characteristics when irradiated with a light amount of cm ² , the open end voltage is 0.498 V and the short circuit current density is 27.0 mA.
/ Cm ² , fill factor 71.5%, and conversion efficiency 9.6%.

(Example 2) In Example 2, a polycrystalline silicon thin film solar cell similar to that of Example 1 was produced. That is, except that the film forming conditions of the polycrystalline silicon thin film photoelectric conversion layer 205 were changed in the second embodiment, the film forming conditions and the device structure of the other layers were the same as those in the first embodiment.
It was exactly the same as.

The polycrystalline silicon thin film photoelectric conversion layer 205 in Example 2 was deposited by the RF plasma CVD method using a 13.56 MHz high frequency power source. In the reaction gas, silane and hydrogen were mixed at a flow rate ratio of 1: 120, and the reaction chamber pressure was adjusted to 5.0 Torr. The discharge power density is 120 mW / cm ² , and the film formation temperature is 40
It was set to 0 ° C. Under such film forming conditions, the film forming rate of the polycrystalline silicon thin film photoelectric conversion layer 205 is 23 nm.
/ Min. Further, regarding this photoelectric conversion layer 205, X
(11) for the (220) diffraction peak obtained by line diffraction
1) The intensity ratio of diffraction peaks was 1/30, and the hydrogen content determined by secondary ion mass spectrometry was 1.6 atom%.

As the incident light 209, AM1.5 light of 100 mW / m is applied to the polycrystalline silicon thin film solar cell of the second embodiment.
In the output characteristics when irradiated with a light amount of cm ² , the open end voltage is 0.520 V and the short circuit current density is 27.4 mA.
/ Cm ² , fill factor 75.1%, and conversion efficiency 1
It was 0.5%.

Examples 3 to 8 Examples 1 to 2 are the same as Examples 3 to 8 except that the conditions for forming the polycrystalline silicon thin film photoelectric conversion layer 205 are changed to those shown in Table 1. A polycrystalline silicon thin film solar cell was fabricated on a glass substrate in the same manner as in. Table 2 shows the physical properties of the polycrystalline silicon thin film photoelectric conversion layer 205 formed in Examples 3 to 8 and the characteristics of the solar cell manufactured including the same. In addition, in Tables 1 and 2, film forming conditions relating to Examples 1 and 2, physical properties of a film formed under the conditions, and various characteristics of a solar cell including the film are also shown.

[0042]

[Table 1]

[0043]

[Table 2]

(Comparative Examples 1 to 4) Comparative Examples 1 to 4 are the same as Examples 1 to 8 except that the polycrystalline silicon thin film photoelectric conversion layer was formed under the film forming conditions shown in Table 3. A polycrystalline silicon thin film solar cell was produced on a glass substrate as in the case. Table 4 shows the physical properties of the polycrystalline silicon thin films formed in Comparative Examples 1 to 4 and various characteristics of solar cells including the same.

[0045]

[Table 3]

[0046]

[Table 4]

As can be seen from Tables 3 and 4, in Comparative Example 1, since the photoelectric conversion layer was formed under the conventional film formation conditions, the film formation rate was slow, and a solar cell including the photoelectric conversion layer was also used in the Example. The photoelectric conversion efficiency is lower than that of. In Comparative Example 2, since the discharge power was increased, the film formation rate of the photoelectric conversion layer was increased, but the photoelectric conversion efficiency of the solar cell including the photoelectric conversion layer was significantly reduced. In Comparative Example 3, since the reaction chamber pressure and the discharge power were both increased, the film formation rate of the photoelectric conversion layer was high. However, since the flow rate ratio of silane and hydrogen was the same as before, the photoelectric conversion layer was The photoelectric conversion efficiency of the solar cell including it is further reduced. In Comparative Example 4, the discharge power was increased, but the gas flow rate ratio of silane to hydrogen was significantly reduced and the pressure was the same as before, so that the film formation rate of the photoelectric conversion layer was reduced, and The conversion efficiency of the solar cell including the photoelectric conversion layer is further reduced.

(Embodiment 9) A method of manufacturing a crystalline silicon thin film solar cell including the step of forming the crystalline silicon thin film photoelectric conversion layer 205 at a low temperature and at a high speed as shown in the above-described Examples 1 to 8 is as follows. It is also useful for manufacturing a tandem solar cell in which amorphous silicon-based photoelectric conversion units whose manufacturing processes are substantially similar are further laminated. Figure 2
In Example 9 corresponding to the above embodiment, a tandem in which an amorphous photoelectric conversion unit 412 including an amorphous silicon photoelectric conversion layer 414 composed of a non-doped layer having a thickness of 0.3 μm is laminated on a polycrystalline silicon thin film photoelectric conversion unit 411. Type solar cell, under the same light irradiation conditions as in Example 1 above, an open-ended voltage of 1.40 V, 1
Short circuit current density of 3.4 mA / cm ² and 14.0%
The conversion efficiency of was obtained.

[0049]

As described above, according to the present invention, when the silicon-based thin film photoelectric conversion layer containing a crystalline material is formed at a low temperature by the plasma CVD method, the film formation rate is significantly improved as compared with the prior art. Since it is possible to obtain a better film quality, it can greatly contribute to both high performance and cost reduction of the silicon-based thin film photoelectric conversion device.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a crystalline silicon-based thin film photoelectric conversion device according to one embodiment of the present invention.

FIG. 2 is a schematic perspective view showing an amorphous silicon thin film / crystalline silicon thin film tandem photoelectric conversion device according to another embodiment of the present invention.

FIG. 3 is a schematic perspective view showing an amorphous silicon thin film / crystalline silicon thin film type tandem photoelectric conversion device according to still another embodiment of the present invention.

[Explanation of symbols]

201, 401, 601: substrates 202, 402, 602 made of glass or the like: films 203, 403, 603 made of Ag or the like 204, 404, 604 made of ZnO or the like 204: for example, n-type first conductivity type microcrystalline silicon layer 205, 405, 605: crystalline silicon photoelectric conversion layers 206, 406, 606: for example p-type reverse conductivity type polycrystalline silicon layers 207, 407, 607: transparent conductive films 208, 408 such as ITO, comb-shaped electrodes 209 such as Ag, 409, 609: Irradiated light 210, 410, 610: Backside electrodes 211, 411, 611: Crystalline silicon photoelectric conversion units 412, 612: Amorphous silicon photoelectric conversion units 413, 613: For example, n-type first conductivity type silicon-based layer 414, 614: i-type amorphous silicon photoelectric conversion layers 415, 615: for example, p-type reverse conductivity Silicon-based layer

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-5-63221 (JP, A) JP-A-9-162431 (JP, A) JP-A-62-171418 (JP, A) JP-A-7- 45540 (JP, A) JP-A-2-54922 (JP, A) JP-A-2-231773 (JP, A) JP-A-5-67797 (JP, A) JP-A-4-137725 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 31/04-31/078

Claims (4)

(57) [Claims] 1. A method for manufacturing a silicon-based thin-film photoelectric conversion device, the photoelectric conversion device includes at least one photoelectric conversion unit formed on a substrate, the photoelectric conversion units high
A one-conductivity-type semiconductor layer sequentially laminated by a frequency plasma CVD method, a silicon-based thin film photoelectric conversion layer containing a crystalline material, and a reverse-conductivity-type semiconductor layer, wherein the photoelectric conversion layer is formed by the plasma CVD method. As the deposition conditions, the base temperature is 550 ° C or lower, the silane-based gas and the hydrogen gas are contained as the main components of the gas introduced into the plasma reaction chamber, and the flow rate of the hydrogen gas with respect to the silane-based gas is 50 times or more. The pressure in the plasma reaction chamber is set to 3 Torr or more, and the high frequency is 0.05 at a frequency of 150 MHz or less.
W / cm ² or more power is applied, elements, 0.5 at 16 nm / min or faster in the thickness direction
The photoelectric conversion layer is deposited to a film thickness within a range of 20 μm.
Is a microcrystalline silicon film with a volume crystallization fraction of 80% or more.
And contains 0.5 atomic% or more and 30 atomic% or less of hydrogen
A method for manufacturing a silicon-based thin-film photoelectric conversion device, which is formed as 2. The pressure in the plasma reaction chamber is 5 Tor.
2. The method for manufacturing a silicon-based thin film photoelectric conversion device according to claim 1, wherein the value is set to r or more. 3. The photoelectric conversion layer is (1
10. The preferred crystallographic orientation plane of 10), wherein the intensity ratio of the (111) diffraction peak to the (220) diffraction peak in X-ray diffraction is 1/10 or less.
Or the method of manufacturing a silicon-based thin-film photoelectric conversion device according to 2. 4. A tandem type photoelectric conversion device is obtained by stacking the photoelectric conversion unit and an amorphous silicon type photoelectric conversion unit.
4. The method for manufacturing a silicon-based thin film photoelectric conversion device according to any one of item 3 .