Cis-based thin film solar battery and process for producing the same

Abstract

This invention provides a CIS-based thin film solar battery and a process for producing the same in which the formation of an alkali barrier layer and a metal backside electrode layer is carried out at a low cost in a short time to prevent such an unfavorable phenomenon that a light absorbing layer is separated from the interface of the light absorbing layer and the metal backside electrode layer. The CIS-based thin film solar battery (1) comprises a glass substrate (2), an alkali-free layer (7) such as silica, a metal backside electrode layer (3) having a laminate structure, a p-type CIS-based light absorbing layer (4), a high-resistance buffer layer (5), and an n-type window layer (6) stacked in that order. The layer (7), either alone or together with a first layer (3a) in the layer (3), can function as an alkali barrier layer (8) that can prevent and control the thermal diffusion of an alkali component into the light absorbing layer during the formation of the layer (4) from the substrate (2). In the layer (3a), crystal grains are fine and has high density. After the formation of the layer (7) on the substrate by RF or DC sputtering, the layer (3)is continuously formed on the layer (7) by DC sputtering.

Description

technical field [0001] The present invention relates to an alkali barrier layer of a CIS type thin film solar cell (when a light absorbing layer is deposited on a metal back electrode layer, the alkali barrier layer barriers and controls alkali formation from a glass substrate below the metal back electrode layer Diffusion) and methods of forming the layer. Background technique [0002] The present invention relates to a CIS-type thin-film solar cell with a pn heterojunction, comprising: as a light-absorbing layer, such as a P-type semiconductor of a multi-element compound semiconductor thin film, especially I-III-VI 2 chalcopyrite semiconductors, for example, copper indium diselenide (CuInSe 2 ), copper indium gallium diselenide (CuInGaSe 2 ), copper gallium diselenide (CuGaSe 2 ), copper indium gallium dithiosulfide (Cu(InGa)(SSe) 2 ), copper indium disulfide (CuInS 2 ), copper gallium disulfide (CuGaS 2 ), copper indium gallium disulfide (CuInGaS 2 ), or with coppe...

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Problems solved by technology

[0004] However, there are only a small number of publications / reports on research on alkali barrier layers, and no reports teach the necessity of alkali barrier layers in the formation of light-absorbing layers by multi-source co-evaporation

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