Photoelectric conversion apparatus and method for manufacturing the same

Abstract

This invention provides a photoelectric conversion apparatus, which can realize a stably high photoelectric conversion efficiency using a transparent electrode having an optimized relationship between electrical resistivity and transmittance, and a method for manufacturing the same. At least one of transparent electrodes (12, 16) is formed of a Ga-free ZnO layer or a Ga-added ZnO layer. The content of Ga in the ZnO layer is not more than 5 atomic% based on Zn in the ZnO layer. The ZnO layer is formed by a sputtering method using an oxygen-containing rare gas as a sputtering gas. The content of oxygen in the sputtering gas is not less than 0.1% by volume and not more than 5% by volume based on the total volume of the oxygen and rare gas.

Description

technical field [0001] The present invention relates to a photoelectric conversion device including a transparent electrode mainly containing ZnO (zinc oxide) and a method for manufacturing the same. Background technique [0002] Conventionally, silicon-based thin-film photoelectric conversion devices are known as photoelectric conversion devices such as solar cells. In this photoelectric conversion device, generally, a first transparent electrode, a silicon-based semiconductor layer (photoelectric conversion layer), a second transparent electrode, and a metal electrode film are sequentially stacked on a substrate. [0003] As a transparent electrode, it is required to use materials with low resistance and high transmittance, usually ZnO (zinc oxide), SnO 2 (tin oxide), ITO (indium oxide tin oxide composite oxide) and other oxide-based transparent conductive films. In order to realize such a low resistance of the transparent electrode, gallium oxide, aluminum oxide, fluori...

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Problems solved by technology

[0006] However, although gallium oxide or aluminum oxide is added to achieve low resistance of the transparent electrode, there is a problem that the transmittance decreases.

In this way, even if Ga or Al is added to the oxide-based transparent conductive film, the resistivity and transmittance show opposite characteristics, and it is difficult to achieve both resistivity and transmittance.

[0007] In addition, in the above-mentioned Patent Document 1, in a solar cell in which the photoelectric conversion layer is made of amorphous silicon, when 0.5 atomic % of Ga is added to Zn in a transparent conductive film mainly composed of ZnO, there is no difference between Compared with the case where Ga is added, the data show that the photoelectric conversion efficiency is increased (Example 4 to Example 6 in Table 2), but this technology is only for the purpose of lowering the temperature when forming a transparent conductive film. Research

That is to say, the above technology does not pay attention to the effect of Ga addition on the interface characteristics between the photoelectric conversion layer and the transparent electrode composed of Ga-added ZnO, and the effect on the resistivity and transmittance of Ga-added ZnO. , not to study the amount of Ga added with the aim of increasing the photoelectric conversion efficiency

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