JPS595679A - Photoelectric transducer device - Google Patents

Abstract

PURPOSE:To provide a highly efficient photoelectric transducer device, by forming a-Si including oxygen atoms in the first doping layer which is to be formed on ITO (Indium Tin Oxide) or SnO2, thereafter forming the same conductive type a-Si, which does not include oxygen. CONSTITUTION:The concentration of B2H6, which is used for obtaining a P type by 20% SiH4 that is dilluted by an H2 base, is made to be 0.05-1% with respect SiH4. O2 is made to be 2-10vol% with respect to SiH4. This gas is made to act on a substrate at a temperature of 200 deg.C, and a P type a-Si layer with a thickness of 50Angstrom is formed. At this time, suppression effect of SiO or SiO2 is made conspicuous by mixing oxygen, and the increase in series resistance can be prevented when a solar battery is manufactured. The thickness of ordinary P type a-Si 10, in which oxygen atoms are not introduced, is 50Angstrom . The sum of the P type layer is 100Angstrom . In this way, the light absorbing loss is made to be about a half in comparison with the case only the ordinary P type a-Si is used. The P-I interface is not different from the ordinary element. The resistance can be made smaller than a single oxygen doped P type a-Si. The increase in the series resistance can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an amorphous silicon (hereinafter referred to as a-8i) solar cell and a photoelectric conversion device in which a-8i is formed on a transparent conductive film.

Conventionally, ITO (Indium Tin Oxide)
) on a transparent conductive film such as SnO2.
There is a solar cell with an i-film formed thereon. Figure 1 shows an example of this, in which 1 is a glass substrate, 2 is ITO only,
It is a transparent conductive film made of 5nOz or a two-layer film of ITO and SnO2. About 100 p-type amorphous Si films are formed on the transparent conductive film 2. This p-type layer 3 is made of Si
It is formed by a glow discharge method using a mixed gas of H4 and B2H6.

Thereafter, an a-8i film 4 of type or nearly t-type is formed, and an a-Si film 6 of n-type is formed. i-type a-Si
Film 4 is formed by glow discharge of SiH4, and film 6 is formed by SiH4 glow discharge.
It is formed by glow discharge of a mixed gas of 4 and PH. Reference numeral 6 denotes a metal electrode, which is formed, for example, by vacuum evaporating aluminum.

In a solar cell having such a configuration, light is made to enter from the glass 1 side. However, as is well known in the 9-layer 3, when the boron concentration is increased in order to lower the series resistance, the optical forbidden band width becomes smaller and the light absorption loss increases. For this reason, the boron concentration is reduced to maintain a large optical band gap. However, this increases the activation energy of poron, causing loss due to a decrease in open-circuit voltage and an increase in series resistance, but since the characteristics are still better than when the boron concentration is high, a low concentration of boron doping is used as a compromise. There is. 1 Recently, it has been reported that a highly efficient solar cell was developed by introducing carbon (for example, CH4) together with SiH4 and B2H6 to increase the optical band gap and use a p-type layer.

That is, 3 in FIG. 1 is replaced with p-type a-8iC:H. In this way, a with a large optical band gap
-SiC: High efficiency is achieved by significantly reducing the light absorption rate in the p layer using H. Further, in the same way as by adding carbon, the optical band gap of the p layer can also be increased by adding oxygen atoms.

However, by adding these impurities, it is possible to control the valence electrons as a p-type, and it has a great effect of reducing light absorption loss by increasing the optical band gap, but the resistance is still relatively large. If it is too thick, it will create series resistance and deteriorate the solar cell characteristics. Also ITO and 5n
Special opening A59-5679 (
2) For example, when SiH4 diluted with H2 is formed by a high frequency glow discharge method, ITO or SnO2 and p-type a-8
It has been found that a substance having a composition of SiO or SiO2 is formed near the i interface, and that In'p Sn is further deposited up to the pi and pi interfaces (1982 Spring Research: Matsushita). SiQ or S102 is considered to become a series resistance of the element, and In and Sn are considered to be undesirable as they become a carrier recombination level at the p or pL interface. The SiO
It has also been shown that the formation of Sin and the movement of In and Sn can be observed even at deposition temperatures of 160 to 300'C.

An object of the present invention is to provide a highly efficient photoelectric conversion device that solves the above problems.

An embodiment of the solar cell according to the present invention will be described below with reference to FIG. In Figure 2, 7 is glass, 8 is ITO, a single layer structure of SnO2, or ITO and 5n.
02 conductive layer with a two-layer structure. 9 is a p-type a-8i into which oxygen atoms are introduced, and is formed as follows. That is, 82H6 for 20% Si Kameki p-type device diluted with H2 base is 0.05 to 1% to SiH4.
The concentration of 02 is 2~10v01% for SiH4.
A p-type A-8i layer of 60 layers was formed by applying the gas to the substrate at a temperature of 200'C.

By mixing oxygen at this time, the above-mentioned effect of suppressing SiO or Si02 is remarkable, and therefore, when a solar cell is produced, an increase in series resistance can be prevented.

1o is a normal p-type>-8i without introducing oxygen atoms, and its thickness is assumed to be 50. In other words, the total thickness of the p-type layer is 100. By doing this, the optical absorption loss can be reduced to about half compared to the case where only normal p-type a-5i is used, and the pi interface is no different from that of a normal element, and the resistance is also the same as that of a single oxygen-doped p-type a-5i. 8i, and it is also possible to avoid an increase in series resistance.

(Assuming the B2H6 concentration in this case).

Reference numeral 11 denotes a high-resistance layer of intrinsic or near-intrinsic T-type a-8i, in which a valence electron control impurity is usually introduced, if not in an extremely small amount. For example, H2 dilution 2
0% SiH4 is formed using a high frequency glow discharge method.

The thickness is, for example, 500 to 1σ000 people. 1
2 is n-type a-8i. 14 is a heavy chain, for example A
vacuum evaporated.

In addition, in the above embodiment, ITO-? We have described an example in which p-type a-5i is first deposited on 5n02. First, n-type Wb-8i containing oxygen is deposited, and then n-type pore-8i, i-type a-8i, p which does not contain oxygen is deposited. shape a
It goes without saying that an element formed in the order of -8i may be produced.
i and then the same conductivity type h-3i which does not contain oxygen
It has a great feature in that it forms a . That is, the present invention provides SiH on a substrate such as ITO or 5n02.
By depositing a mixture of oxygen or at least a compound containing oxygen in addition to a mixed gas of 4 and B2H6, the generation of substances such as SiO and Sin can be suppressed, and the optical band gap can be improved by oxygen. High-performance solar cells can be achieved by reducing light absorption loss by using an increased p-layer and subsequently forming p-type a-8i, i-type a-8i, and n-type a-5i that do not introduce oxygen. can be formed.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a photoelectric conversion device according to a conventional example;
The figure is a configuration diagram of a photoelectric conversion device according to an embodiment of the present invention. 7...Glass, 8...Photoconductive layer, 9.
...p type a -8i, 10 ・------p
Type L-8i, 11... River, Type 1 a-5i, 12... Mountain...
electrode. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (2)

[Claims] (1) A photoelectric conversion device in which a transparent conductive film is disposed on a substrate, and an amorphous silicon film to which oxygen atoms are introduced and an amorphous silicon film to which no oxygen is introduced are sequentially formed on the transparent conductive film. (2) The conductive type valvus silicon film with oxygen atoms introduced onto the transparent conductive film, the conductive type valvus crystalline silicon film without introducing oxygen atoms, the intrinsic or near-intrinsic amorphous silicon film, the conductive type valvate silicon film with oxygen atoms introduced thereon; Valve crystalline silicon film of conductivity type opposite to shape,
The photoelectric conversion device according to claim 1, wherein the electrodes are sequentially arranged.