METHOD FOR FABRICATING HIGH EFFICIENCY FLEXIBLE COMPOUND SEMICONDUCTOR THIN FILM SOLAR CELL WITH CHALCOPYRITE SYSTEM

摘要

Provided is a method for fabricating a high-efficiency flexible thin film solar cell using a chalcopyrite-based compound semiconductor, including: forming a sacrificial layer on a substrate; forming a solar cell structure including a diffusion barrier dielectric on the top of the sacrificial layer; forming a support film on the top of the solar cell structure; carrying out selective etching of the sacrificial layer to separate the solar cell structure and the support film from the substrate; and integrating the solar cell structure with a heterogeneous flexible host substrate and removing the support film. In the high-efficiency flexible thin film solar cell using a chalcopyrite-based compound semiconductor according to the present disclosure, the thin film of GaAs diffusion barrier dielectric prevents diffusion of impurities since it has an optimized thermal expansion coefficient with reference to the CIGS (Cu(In,Ga,Al)(Se,S)) absorption layer and the lower electrode molybdenum layer, and inhibits lower electrode cracking and CIGS layer separation caused by the difference of thermal expansion coefficient of the CIGS layer, thereby improving the efficiency of the solar cell. In addition, the method uses heterogeneous integration technology and epitaxial lift off (ELO) that enables recycle of a substrate, and thus it is possible to provide a high-efficiency flexible thin film solar cell having improved cost efficiency and flexibility.