JP3100668B2 - Method for manufacturing photovoltaic element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ip, in, pin,
nip, pinpin, nipnip, pinpinp
The present invention relates to a method for manufacturing a photovoltaic element including a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer such as an in, nipnipnip junction.

[0002]

2. Description of the Related Art Conventionally, ip, in, pin, nip, p
inpin, nipnip, pinpinpin, ni
In the manufacture of a photovoltaic element comprising a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer such as a pnipnip junction, a junction between an i-type non-single-crystal semiconductor layer and a p-type or n-type non-single-crystal semiconductor layer Was formed by depositing and stacking each non-single-crystal semiconductor layer. That is, a p-type or n-type non-single-crystal semiconductor layer is deposited after depositing an i-type non-single-crystal semiconductor layer, or an i-type non-single-crystal semiconductor layer is deposited after depositing a p-type or n-type non-single-crystal semiconductor layer. To form a junction of a non-single-crystal semiconductor.

For example, conventionally, in order to manufacture a photovoltaic element made of amorphous silicon having a structure in which n, i, and p-type non-single-crystal semiconductor layers are stacked in this order on a substrate, an n-type amorphous silicon layer is formed on the substrate. , After sequentially depositing an i-type amorphous silicon layer, a gas such as SiH ₄ containing Si as a main element of the p-type non-single-crystal semiconductor layer and an impurity for imparting a p-type conductivity type to the i-type amorphous silicon layer Depositing a p-type amorphous silicon layer by glow discharge of a mixed gas with a gas such as BF ₃ containing an element,
A nip junction structure of amorphous silicon was formed.

However, in such a conventional method of film deposition, there is a limit in depositing a non-single-crystal semiconductor layer over a large area uniformly and with good reproducibility, and it is inevitably too thin or too thick as desired. Variations in the film thickness and unevenness in the film thickness depending on the location are liable to occur, which causes unevenness and unevenness in the element characteristics.

In order to deposit a non-single-crystal semiconductor layer extremely thinly, it is necessary to reduce the deposition time or the deposition rate. However, if the film deposition time is shortened, the film is deposited before the film formation conditions are unstable, and the reproducibility of the film thickness is impaired, and the film thickness tends to vary. If the supply amount is small, it is difficult to uniformly supply the raw material of the film over a large area, and the film thickness tends to be uneven.

In particular, in a photovoltaic element, an impurity-doped layer disposed on the light incident side of the i-type non-single-crystal semiconductor layer has a light quantity entering the i-type non-single-crystal semiconductor layer due to light absorption by the impurity-doped layer. In order to prevent the reduction, the layer thickness must be reduced to the minimum necessary.

However, it is difficult to control the film thickness by the conventional method of depositing a film, and the film thickness of the impurity-doped layer becomes uneven or uneven, resulting in large unevenness or unevenness in the element characteristics such as short-circuit current and open voltage. There were many things.

On the other hand, as another method for forming a p-type or n-type non-single-crystal semiconductor layer, an ion implantation method is conventionally known. According to the ion implantation method, the thickness of the p-type or n-type non-single-crystal semiconductor layer can be controlled by controlling the intensity of implanting impurity ions by an acceleration voltage, but an ion implantation device for implanting impurity ions is used. Is
Generally, the system consists of a system for generating ions, a system for extracting ions in the form of beams, and a system for scanning beams. Such a large-area photovoltaic element is not suitable for manufacturing with good productivity at low cost, and has not been adopted as a means for forming an impurity-doped layer.

[0009] A non-single-crystal silicon is used for the 29p-MF-9 in the 51st Annual Meeting of the Japan Society of Applied Physics, 1990, using a large-area ion doping apparatus that accelerates ions in the form of a shower instead of a beam. A method of manufacturing a thin film transistor in which a film is doped with impurities is disclosed, and it is disclosed that the doping area can be increased and the device can be simplified as compared with a conventional general ion implantation method.

However, even in this manufacturing method, an ion accelerator system is required to extract ions at an acceleration voltage of several kV, accelerate the ions, and drive the ions into the semiconductor film. Later, post-treatment of thermal annealing was required.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in a method of manufacturing a photovoltaic device comprising a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer. A p-type or n-type non-single-crystal semiconductor layer is formed on the non-single-crystal semiconductor layer in a thin and uniform thickness with good reproducibility, and a photovoltaic element can be obtained over a large area without unevenness of the device characteristics and with good reproducibility. To provide a manufacturing method.

Another object of the present invention is to provide a manufacturing method which realizes the above-mentioned object by an apparatus having a simple structure without excessive investment in equipment and without post-processing such as thermal annealing. It is in.

[0013]

A method for manufacturing a photovoltaic device according to the present invention is a method for manufacturing a photovoltaic device comprising a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer, After depositing and forming the i-type non-single-crystal semiconductor layer,
The i-type non-single-crystal semiconductor layer is moved into a plasma discharge chamber different from the plasma discharge chamber in which the i-type semiconductor single-crystal semiconductor layer is deposited, and the i-type non-single-crystal semiconductor layer is moved into the other plasma discharge chamber. Glow discharge decomposition plasma of a gas containing an impurity element imparting p-type or n-type conductivity and not containing a main component element of the i-type non-single-crystal semiconductor layer, or a mixed gas of the gas and a diluting gas after the i-type exposing a non-single-crystal semiconductor layer surface was allowed form a bond formed <br/> the non-single-crystal semiconductor impurity doped layer without film deposition to, the impurity
Following on the doped layer is provided a transparent conductive film is characterized in Rukoto.

That is, in the manufacturing method of the present invention, after depositing and forming an i-type non-single-crystal semiconductor layer, a p-type or i-type non-single-crystal semiconductor layer is formed on the i-type semiconductor single-crystal semiconductor layer. Instead of depositing a p-type or n-type non-single-crystal semiconductor layer as in the prior art, the i-type semiconductor single-crystal semiconductor layer is deposited.
In a plasma discharge chamber different from the plasma discharge chamber
Type non-single-crystal semiconductor layer is moved to another plasma discharge chamber.
In those that alter the vicinity of the surface of the i-type non-single-crystal semiconductor layer on the p-type or n-type non-single-crystal semiconductor by the plasma treatment.

Here, the plasma treatment is performed by applying a glow discharge plasma of a gas not containing a main component element of the i-type non-single-crystal semiconductor layer or a mixed gas of the gas and the diluting gas to the i-type non-single-crystal semiconductor layer. It is performed by a simple method of exposing the layer surface.

The energy given to the impurity element by the glow discharge plasma is extremely lower than the energy given by the ion implantation method for accelerating ions.
In a glow discharge plasma that does not accelerate ions, the impurity element is doped only from the surface of the i-type non-single-crystal semiconductor layer to a very shallow region .

However, the present inventors have made the surface of the i-type non-single-crystal semiconductor film contain an impurity element which imparts p-type or n-type conductivity to the i-type non-single-crystal semiconductor film, and A sample was prepared by exposing the single crystal semiconductor film to a glow discharge plasma of a gas not containing a main component element, and the distribution of impurity elements in the sample in the thickness direction was examined by secondary ion analysis (SIMS). A layer in which the main element of the i-type layer is doped with an impurity element has been formed over a large area with good uniformity and reproducibility to a depth of several tens to several hundreds of angstroms depending on the plasma formation conditions.

Further, when the present inventors have formed an impurity-doped layer on an i-type non-single-crystal semiconductor layer of a photovoltaic device comprising a junction of a non-single-crystal semiconductor by using such a glow discharge plasma, good device characteristics were obtained. Was obtained.

In a photovoltaic element comprising a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer, the impurity-doped layer is thin because it absorbs less light as long as a sufficient impurity concentration can be obtained. It is more preferable that the method of the present invention forms a good impurity-doped layer by glow discharge plasma which causes little damage to the film and does not require structural relaxation treatment such as thermal annealing.

FIG. 1 is a schematic sectional view showing an example of a manufacturing process according to the manufacturing method of the present invention. In the process of manufacturing a photovoltaic device having a nip junction structure, (a) shows n, i on a substrate.
FIG. 4B shows a state in which a non-single-crystal semiconductor layer of a type is formed by deposition and stacked, and FIG. 4B shows that the surface of the i-type non-single-crystal semiconductor layer is changed from the state of FIG. This figure shows a state after forming a p-type non-single-crystal semiconductor layer by exposing to a glow discharge plasma of a gas containing an impurity element.

In the drawing, 101 is a substrate, 102 is an n-type non-single-crystal semiconductor layer formed by deposition, 103 is an i-type non-single-crystal semiconductor layer formed by deposition, and 104 is the surface of the i-type non-single-crystal semiconductor layer. This is a p-type non-single-crystal semiconductor layer formed by changing the vicinity by plasma treatment.

When a glow discharge of a gas containing an impurity element imparting p-type or n-type conductivity to the i-type non-single-crystal semiconductor layer occurs, the main component of the i-type non-single-crystal semiconductor layer is contained in the gas. Even if no element is contained, for example, when the i-type non-single-crystal semiconductor layer is amorphous silicon, a glow discharge plasma of a gas containing a boron atom that imparts a p-type conductivity to the i-type non-single-crystal semiconductor layer is used. In some cases, a semiconductor film containing an impurity element as a main component may be deposited so that an amorphous boron layer can be deposited.

However, in the manufacturing method of the present invention, in addition to the device having the i-type non-single-crystal semiconductor layer deposited on the substrate, the Corning 7059 glass plate and the single-crystal silicon wafer are exposed to plasma. When plasma treatment was performed simultaneously in the space, the effect of the present invention was clearly confirmed even when no film deposition was observed optically and electrically on Corning 7059 glass plate or single crystal silicon wafer. It was found that when the deposition of the film was observed, the effect was rather reduced.

From the above, it can be confirmed that the effect of the present invention is not due to the deposition of the semiconductor film containing the impurity element as a main component, but to the change of the surface of the i-type non-single-crystal semiconductor layer due to the plasma treatment. Was.

In the present invention, a non-single-crystal semiconductor refers to a semiconductor other than a single crystal, that is, a semiconductor having a structure from amorphous to polycrystalline, and it goes without saying that a so-called microcrystalline semiconductor also falls into this category.

Hereinafter, the case where the i-type non-single-crystal semiconductor layer in the present invention mainly contains an element belonging to Group IV of the periodic table such as Si, SiC, or SiGe will be described in more detail. Examples of the impurity element that imparts p-type conductivity to an i-type non-single-crystal semiconductor layer mainly containing an element of Group IV of the periodic table include B, Al, Ga, In, and Tl of Group III of the periodic table. Examples of the impurity element that imparts the n-type conductivity include P, As, Sb, Bi, and the like, which belong to Group V of the periodic table.

The gas containing these impurity elements may be in a gaseous state at normal temperature and normal pressure, or at least a gas under glow discharge conditions, and may be BF ₃ , a compound which can be easily vaporized by an appropriate vaporizer. BCl ₃ , BBr ₃ ,
B ₂ H ₆ , B ₄ H ₁₀ , AlCl ₃ , PH ₃ , P ₂ H ₅ , PF ₃ ,
PF ₅ , PCl ₃ , AsH ₃ , AsF ₃ , AsF ₅ , AsC
l ₃ , SbH ₃ , SbF _{3, and the} like. One or more of these selected according to the required p and n conductivity types are used for plasma treatment of an i-type non-single-crystal semiconductor layer. Gas.

The plasma processing gas may contain an inert gas such as He, Ne, or Ar for stabilizing the discharge. However, S, which is a main component of the i-type non-single-crystal semiconductor layer, may be used.
Elements such as i, C, and Ge should not be contained because they do not deposit the film.

As described above, the i-type non-single-crystal semiconductor layer corresponds to the first part of the periodic table.
In the case where a group IV element is a main component, an example of a plasma processing gas after forming an i-type non-single-crystal semiconductor layer has been described. In the case of another element or compound, the i-type non-single-crystal A gas containing an impurity element that imparts p-type or n-type conductivity to the semiconductor layer and not containing a main component element of the i-type non-single-crystal semiconductor layer is selected and used.

In the present invention, as an exciting means for generating glow discharge plasma of these gases, known electric energy such as high-frequency discharge, low-frequency discharge, DC discharge, microwave discharge, and thermal energy such as heater heating are used. ,
Means for applying energy such as light energy may be used.

In the present invention, exposing the surface of the i-type non-single-crystal semiconductor layer to the glow discharge plasma means that the impurity element activated by the glow discharge is supplied to the surface of the i-type non-single-crystal semiconductor layer. Is to do
Specifically, this is performed by generating glow discharge plasma of a gas containing an impurity element in a space where an element deposited up to the i-type non-single-crystal semiconductor layer is arranged.

Further, the present inventors have made photovoltaic devices having various structures by the manufacturing method of the present invention an impurity element for imparting p-type or n-type conductivity to the i-type non-single-crystal semiconductor layer of the device. Various types of gases were added to a gas containing, and the following relationship was found while examining the correspondence between the type of gas to be added and the characteristics of the photovoltaic device to be manufactured.

That is, when the hydrogen gas is contained in the gas containing the impurity element that imparts the p-type or n-type conductivity to the i-type non-single-crystal semiconductor layer, the production is made in comparison with the case where the hydrogen gas is not contained. It has been found that the open-circuit voltage of the photovoltaic element increases and the photoelectric conversion efficiency improves.

Ip, in, pin, nip, pinpi
n, nipnip, pinpinpin, nipnip
Photovoltaic devices having any junction structure applicable to the present invention, such as Nip and the like, were manufactured and their device characteristics were measured. In each case, the improvement of device performance was confirmed by the addition of hydrogen gas.

In carrying out the method for manufacturing a photovoltaic device of the present invention, an appropriate apparatus can be used.
As a preferable example, an apparatus having a configuration shown in FIG. 2 can be used.

In FIG. 2, reference numerals 201, 202, and 203 denote plasma discharge chambers made of stainless steel, 204 and 205 denote chambers for loading and unloading substrates, and the respective plasma discharge chambers are connected by a gate valve 206. 20
Reference numeral 7 denotes a substrate, which can move each plasma discharge chamber by a moving mechanism (not shown). Three plasma discharge chambers are used to deposit a non-single-crystal semiconductor layer on the surface or perform plasma processing on the surface of the non-single-crystal semiconductor layer. As a result, a photovoltaic element including a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer is formed. An infrared heater 208 for heating the substrate from the back side in each of the plasma discharge chambers 201 to 203;
A gas introduction pipe 209 for introducing a gas supplied from a gas supply unit (not shown) into the plasma discharge chamber, an exhaust pipe 210 for exhausting the plasma discharge chamber by an exhaust means (not shown), and discharging by applying energy to the gas in the plasma discharge chamber. , A microwave power supply 211 for supplying microwave power, a waveguide 212, and a microwave introduction window 213 made of a dielectric material.

Further, an apparatus for carrying out the manufacturing method of the present invention may be an apparatus having a configuration shown in FIG.

The device shown in FIG. 3 generates glow discharge by using high-frequency power instead of the microwave power of the device shown in FIG. 2, and the devices denoted by reference numerals 301 to 309 in FIG. 209. In this device, high-frequency power is supplied from a high-frequency power supply 311 and causes a discharge between the discharge electrode 312 and the substrate 307.

[0039]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 Using the apparatus shown in FIG. 2, an amorphous silicon photovoltaic device having a nip structure was manufactured on a substrate by the following operation according to the method of the present invention.

First, a stainless steel substrate 207 having a width of 30 cm, a length of 30 cm and a thickness of 0.5 mm was mirror-polished on its surface.
Is set in the supply chamber 204, and then the supply chamber 204, the plasma discharge chambers 201,
02, 203, and all the vacuum chambers of the extraction chamber 205 were sufficiently evacuated from the respective exhaust pipes 210.

Next, the gate valve 206 is opened, and the substrate is moved to the plasma discharge chamber 201.
06 was closed, and while the source gas for the n-type non-single-crystal semiconductor layer was being introduced from the gas introduction pipe 209, the exhaust amount was adjusted to adjust the inside of the plasma discharge chamber 201 to a predetermined pressure.

The substrate 207 is heated to a predetermined temperature by the heater 208, and the microwave is introduced from the microwave introduction window 213 to 2.45 G.
Hz microwave power is introduced to the plasma discharge chamber 201.
A glow discharge plasma was generated in the inside, and an n-type amorphous silicon layer was deposited on the substrate. After the discharge was continued for a predetermined time, the discharge and gas introduction were stopped, and the plasma discharge chamber was sufficiently evacuated.

Subsequently, the substrate was similarly moved to the plasma discharge chamber 202, and an i-type amorphous silicon layer was deposited by microwave glow discharge plasma of a source gas for the i-type non-single-crystal semiconductor layer. Table 1 shows film deposition conditions in each plasma discharge chamber.

[0045]

[Table 1] The substrate on which the film has been deposited up to the i-type non-single-crystal semiconductor layer as described above is moved to the plasma discharge chamber 203,
A mixed gas of BF ₃ containing boron atoms, which is an impurity for imparting a p-type conductivity to the amorphous silicon film of the non-single-crystal semiconductor layer, and He, which is a diluting gas, is supplied through a gas introduction tube 209 to a microwave. Power was introduced from the microwave introduction window 213 into the plasma discharge chamber 203 to generate glow discharge plasma, and the surface of the i-type non-single-crystal semiconductor layer was exposed to the glow discharge plasma to form a p-type layer. Table 2 shows the conditions of the plasma treatment.

[0046]

[Table 2] After the plasma treatment, the substrate on which the amorphous silicon film was deposited was moved to the take-out chamber 205 and taken out of the apparatus.

A 30 cm square substrate on which an amorphous silicon film having a nip junction structure obtained by the above method was formed,
It was cut into 9 pieces each having a size of 0 cm square and put into a vacuum deposition apparatus. An ITO transparent conductive film was formed under the conditions shown in Table 3, and a grid-shaped Ag current collecting electrode was formed by a vacuum deposition method using a mask. The photovoltaic element shown in the schematic sectional view of FIG. 4 was manufactured. 4, reference numeral 401 denotes a stainless steel substrate; 402, an n-type non-single-crystal semiconductor layer; 403, an i-type non-single-crystal semiconductor layer; 404, a p-type non-single-crystal semiconductor layer;
Denotes an ITO transparent conductive film, and 406 denotes a current collecting electrode.

[0048]

[Table 3] According to the above manufacturing method, 10 pieces of 30 cm square stainless steel substrates are put in, 90 pieces of 10 cm square photovoltaic elements are manufactured under the same conditions, and the manufactured photovoltaic elements are AM1.5,
The device characteristics such as open-circuit voltage and short-circuit current of each device were measured under 100 mW / cm ² simulated sunlight.

As a result, the open-circuit voltage and short-circuit current can be reduced by the conventional photovoltaic element in the case where a p-type non-single-crystal semiconductor layer having an appropriate thickness can be formed on the i-type non-single-crystal semiconductor layer. The open circuit voltage is 100 to
102, the short-circuit current was 99 to 101, and good characteristics were obtained with good reproducibility over a large area. After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 203 which was subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. The inside of 203 was not contaminated at all.

COMPARATIVE EXAMPLE 1 As shown in Table 4, the gas introduced into the plasma discharge chamber 203 was changed to contain Si, which is a main component of the i-type non-single-crystal semiconductor layer, and a p-type amorphous silicon layer was deposited. In the same manner as in Example 1 except that the photovoltaic element was formed as above, 90 pieces of 10 cm square photovoltaic elements each having a nip amorphous silicon layer laminated on a stainless steel substrate were manufactured.
The open-circuit voltage and short-circuit current of each element were measured under simulated sunlight of AM 1.5 and 100 mW / cm ² .

[0051]

[Table 4] As a result, the open-circuit voltage and the short-circuit current are reduced by 100 to the characteristic value of the photovoltaic element when a p-type non-single-crystal semiconductor layer having an appropriate thickness can be formed on the i-type non-single-crystal semiconductor layer by a deposition method.
The open-circuit voltage is 91 to 100 and the short-circuit current is 8
There was large unevenness and variation in element performance from 5 to 100 for each input substrate, or depending on the location in the substrate.

After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 203 which had been subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. Film pieces are peeled off from the inner wall and flow inside the plasma discharge chamber 203, and a film adheres to the inner surface of the microwave introduction window 213, and it is difficult to continue the manufacturing without cleaning the inside. It was a situation.

The subsequent experiment was performed in a contaminated plasma discharge chamber 20.
3 The inside was thoroughly cleaned and no film remained.

Example 2 The procedure of Example 1 was repeated except that the gas introduced into the plasma discharge chamber 203 was changed as shown in Table 5 and that the gas containing the impurity element for imparting conductivity to the p-type contained hydrogen gas. Similarly, 90 10 cm square photovoltaic elements in which an amorphous silicon layer having a nip junction structure is laminated on a stainless steel substrate are manufactured, and each element is simulated under simulated sunlight of AM 1.5 and 100 mW / cm ² . The open circuit voltage and short circuit current were measured.

[0055]

[Table 5] As a result, the open-circuit voltage and the short-circuit current are the characteristic values of the photovoltaic element when the p-type non-single-crystal semiconductor layer having an appropriate thickness can be formed on the i-type non-single-crystal semiconductor layer by the conventional deposition method. The open-circuit voltage was 108 to 110 and the short-circuit current was 100 to 101. A photovoltaic element having a high open-circuit voltage and good characteristics was obtained with good reproducibility over a large area without unevenness or variation.

After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 203 which had been subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. The inside of the plasma discharge chamber 203 was not contaminated at all.

Example 3 A stainless steel substrate was loaded from 204 using the apparatus shown in FIG. 2, and p and i type non-single-crystal semiconductor layers were deposited by microwaves in plasma discharge chambers 203 and 202. Then, plasma treatment was performed on the surface of the i-type non-single-crystal semiconductor layer to form an amorphous silicon film having a pin structure. Table 6 shows conditions for forming the p and i layers, and Table 7 shows conditions for plasma treatment of the surface of the i-type non-single-crystal semiconductor layer. After the formation of the amorphous silicon film, an ITO transparent conductive film and a collecting electrode were laminated in the same manner as in Example 1 to manufacture 90 photovoltaic elements from 10 substrates, and AM1.5, 100 mW / c.
under the open voltage of each element of the pseudo sunlight of m ^2, and to measure the short-circuit current.

[0058]

[Table 6]

[0059]

[Table 7] As a result, the open-circuit voltage and the short-circuit current depend on the characteristic value of the photovoltaic element when an n-type non-single-crystal semiconductor layer having an appropriate thickness can be formed on an i-type non-single-crystal semiconductor by a conventional deposition method. As compared with 100, the open-circuit voltage was 100 to 101, and the short-circuit current was 100 to 102. Photovoltaic devices having good characteristics were obtained with good reproducibility over a large area without unevenness or variation.

After the photovoltaic device was manufactured, the inner wall of the plasma discharge chamber 201 subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. The inside of the plasma discharge chamber 201 was not contaminated at all.

Comparative Example 2 As shown in Table 8, the gas introduced into the plasma discharge chamber 201 was changed to contain Si, which is a main component element of the i-type layer, and an n-type amorphous silicon layer was formed by deposition. Except for the above, 90 photovoltaic elements of 10 cm square in which an amorphous silicon layer having a pin junction structure was laminated on a stainless steel substrate were manufactured in the same manner as in Example 3, and AM
The open-circuit voltage and short-circuit current of each element were measured under simulated sunlight of 1.5 and 100 mW / cm ² .

[0062]

[Table 8] As a result, the open-circuit voltage and the short-circuit current are reduced by 100 to the characteristic value of the photovoltaic element when an n-type non-single-crystal semiconductor layer having an appropriate thickness can be formed on the i-type non-single-crystal semiconductor layer by a deposition method.
The open circuit voltage was 85 to 100 and the short circuit current was 8
There was large variation and unevenness in the element performance depending on the input substrate from 0 to 100, or depending on the location in the substrate.

After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 201 subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. Film pieces are peeled off from the inner wall and flow inside the plasma discharge chamber 201, and the film adheres to the inner surface of the microwave introduction window 213, so that it is difficult to continue the production without cleaning the inside. It was a situation.

A subsequent experiment was conducted using the contaminated plasma discharge chamber 20.
1 was carried out after sufficient cleaning of the inside to confirm that no film remained.

Example 4 Ninety photovoltaic elements were manufactured in the same manner as in Example 3 except that the gas for the plasma treatment was changed to hydrogen gas as shown in Table 9, and AM 1.5, 100 mW / cm ² The open-circuit voltage and short-circuit current of each element were measured under simulated sunlight.

[0066]

[Table 9] As a result, the open-circuit voltage and short-circuit current were 113 to 114, and the open-circuit voltage and short-circuit current were 113 to 114, respectively, when the value obtained when an n-type non-single-crystal semiconductor layer having an appropriate thickness could be formed by a deposition method was 100. The open-circuit voltage was as high as 100 to 101, and a photovoltaic element having good characteristics was obtained with good reproducibility over a large area without unevenness or variation.

After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 201 which had been subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. The inside of the plasma discharge chamber 201 was not contaminated at all.

Example 5 FIG. 2 was changed except that the energy source for discharging was changed to a high frequency power source.
The n and i layers are deposited under the conditions shown in Table 10 using the same apparatus shown in FIG. 3 and subjected to plasma treatment under the conditions shown in Table 11, and a 10 cm square photovoltaic film made of amorphous silicon is formed on a stainless steel substrate. 90 power elements were manufactured and AM
The open-circuit voltage and short-circuit current of each element were measured under simulated sunlight of 1.5 and 100 mW / cm ² .

[0069]

[Table 10]

[0070]

[Table 11] As a result, the open-circuit voltage and short-circuit current were 114 to 115, and the open-circuit voltage and short-circuit current were 114 to 115, respectively. A photovoltaic element having characteristics as good as 100 to 101 was obtained over a large area with good reproducibility without unevenness or variation.

After the manufacture of the photovoltaic element, the inner wall of the plasma discharge chamber 303 subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. The inside of the plasma discharge chamber 303 was not contaminated at all.

Comparative Example 3 A stainless steel substrate was formed in the same manner as in Example 5 except that the gas introduced into the plasma discharge chamber 303 was changed as shown in Table 12, and a p-type amorphous silicon layer was formed by deposition. 90 pieces of 10 cm square photovoltaic elements were manufactured by laminating an amorphous silicon layer with a nip junction structure, and the open-circuit voltage and short-circuit current of each element were measured under simulated sunlight of AM 1.5 and 100 mW / cm ^2. did.

[0073]

[Table 12] As a result, the open-circuit voltage and the short-circuit current were 88 to 100, and the open-circuit voltage and the short-circuit current were 88 to 100, respectively. From 85 to 100, there was a great variation and unevenness in the element performance depending on each input substrate or depending on the location in the substrate.

After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 303 that had been subjected to the glow discharge plasma treatment was analyzed by optical and electrical means. As a result, the adhesion of the p-type amorphous silicon film and the polysilane powder was observed. As a result, the inside of the plasma discharge chamber 303 was considerably contaminated.

The subsequent experiment was performed in the contaminated plasma discharge chamber 30.
3 The cleaning was performed in a state where the inside was sufficiently cleaned and no film remained.

Example 6 A stainless steel was produced in the same manner as in Example 5 except that the conditions for forming the i-type non-single-crystal semiconductor layer were changed as shown in Table 13 and the i-type non-single-crystal semiconductor layer was changed to amorphous silicon germanium. 90 photovoltaic elements of 10 cm square were manufactured on the substrate, and the open-circuit voltage and short-circuit current of each element were measured under simulated sunlight of AM 1.5 and 100 mW / cm ² .

[0077]

[Table 13] As a result, the open-circuit voltage and the short-circuit current were 113 to 114, and the open-circuit voltage and the short-circuit current were 113 to 114, respectively. Photovoltaic elements having characteristics as good as 100 to 102 were obtained with good reproducibility without unevenness or variation.

After the manufacture of the photovoltaic element, the inner wall of the plasma discharge chamber 303 subjected to the glow discharge plasma treatment was analyzed by optical and electrical means, but no film or powder was found to adhere. The inside of the plasma discharge chamber 303 was not contaminated at all. Example 7 An i-type non-single-crystal semiconductor layer was formed on a stainless steel substrate in the same manner as in Example 5 except that the conditions for forming the i-type non-single-crystal semiconductor layer were changed as shown in Table 14, and the i-type non-single-crystal semiconductor layer was changed to amorphous silicon carbon. 90 photovoltaic elements of 10 cm square were manufactured, and AM
The open-circuit voltage and short-circuit current of each element were measured under simulated sunlight of 1.5 and 100 mW / cm ² .

[0079]

[Table 14] As a result, the open-circuit voltage and the short-circuit current are 110 to 111, and the open-circuit voltage and the short-circuit current are 110 to 111, respectively, when the value obtained when a p-type non-single-crystal semiconductor layer having an appropriate film thickness can be formed by a deposition method is 100. Photovoltaic devices having characteristics as good as 100 to 101 were obtained with good reproducibility without unevenness or variation.

After the photovoltaic element was manufactured, the inner wall of the plasma discharge chamber 303 which had been subjected to the glow discharge plasma treatment was analyzed by optical and electrical means, but no film or powder was found to adhere. The inside of the plasma discharge chamber 303 was not contaminated at all.

[0081]

As described above, according to the method for manufacturing a photovoltaic device of the present invention, a method for manufacturing a photovoltaic device comprising a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer is provided. A p-type or n-type non-single-crystal semiconductor layer can be formed on the i-type non-single-crystal semiconductor layer over a large area with a thin and uniform film thickness with good reproducibility, and there is almost no unevenness or variation in device characteristics. An electromotive element can be manufactured over a large area with good reproducibility.

Further, according to the method for manufacturing a photovoltaic element of the present invention, the above effects can be obtained by an apparatus having a simple configuration without excessive capital investment and without post-treatment such as thermal annealing. Can be.

Further, according to the method of manufacturing a photovoltaic device of the present invention, the inside of the plasma discharge chamber for forming the p-type or n-type non-single-crystal semiconductor layer on the i-type non-single-crystal semiconductor layer is contaminated. Without a large number of photovoltaic elements can be manufactured continuously without cleaning the inside of the manufacturing equipment,
Equipment productivity can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a manufacturing process according to a manufacturing method of the present invention.

FIG. 2 is a schematic diagram showing an example of a plasma discharge device for realizing a method for manufacturing a photovoltaic element according to the present invention.

FIG. 3 is a schematic diagram showing another example of a plasma discharge device for realizing the method for manufacturing a photovoltaic element of the present invention.

FIG. 4 is a schematic perspective view showing a layer configuration of a photovoltaic element manufactured by performing the method of the present invention.

[Explanation of symbols]

101, 207, 307, 401 Substrate 102, 402 n-type non-single-crystal semiconductor layer 103, 403 i-type non-single-crystal semiconductor layer 104, 404 p-type non-single-crystal semiconductor layer 201, 202, 203, 301, 302, 303
Plasma discharge chamber 204, 205, 304, 305 Substrate loading / unloading chamber 206, 306 Gate valve 208, 308 Infrared heater 209, 309 Gas introduction pipe 210, 310 Exhaust pipe 211 Microwave power supply 212 Waveguide 213 Microwave introduction window 311 High frequency power supply 312 Discharge electrode 405 ITO transparent conductive film 406 Current collecting electrode

Continuation of the front page Judge, Hidetomo Higashimori Judge, Motofumi TABE Judge, Ms. Ayako Aoyama (56) References JP-A-58-9321 (JP, A) JP-A-2-252235 (JP, A) -125681 (JP, A) JP-A-4-299576 (JP, A) JP-A-55-78524 (JP, A)

Claims (3)

(57) [Claims] 1. A method for manufacturing a photovoltaic element comprising a junction of a non-single-crystal semiconductor including at least an i-type non-single-crystal semiconductor layer, wherein the i-type non-single-crystal semiconductor layer is deposited and formed. The i-type non-single-crystal semiconductor layer is moved to a plasma discharge chamber different from the plasma discharge chamber where the semiconductor single-crystal semiconductor layer is deposited, and the i-type non-single-crystal semiconductor layer is p-type or The glow discharge decomposition plasma of a gas containing an impurity element imparting an n-type conductivity and not containing a main component element of the i-type non-single-crystal semiconductor layer, or a mixed gas of the gas and a diluting gas is used. exposing the mold non-single-crystal semiconductor layer surface, after brought form a bond before <br/> Symbol non-single crystal semiconductor to form an impurity doped layer without film deposition, the impurity de
Method of producing a photovoltaic element characterized Rukoto a transparent conductive film following the-loop layer. 2. The method according to claim 1, wherein the diluting gas contains hydrogen gas. 3. The plasma discharge chamber for depositing the i-type non-single-crystal semiconductor layer and another plasma discharge chamber for depositing the i-type non-single-crystal semiconductor layer are connected by a gate valve. The method for manufacturing a photovoltaic device according to claim 1.