Mesh-type transparent CZTSSe thin-film solar cell

Abstract

The field of building-integrated photovoltaic (BIPV) power generation is currently being actively researched. In particular, the development of transparent solar cells shows the possibility that the installation of solar power facilities outside the building, which was limited to roofs, can replace windows with solar facilities beyond walls. This leads to the growth of the BIPV market, and as a result of research on transparent solar cells using various solar cells, the development of prototypes is reported. Among them, the field of thin-film solar cells has been studied steadily as solar cells applicable to the next generation BIPV with lightweight as a weapon. Cu(In,Ga)Se2 (CIGS) thin-film solar cell is a representative research field for thin-film solar cells based on stable efficiency and being commercialized in some fields such as aerospace and BIPV. Many studies have been actively reported to obtain transparency by thinning the absorption layer or forming hole patterns using laser etching. However, there is a disadvantage in that the manufacturing cost is high because In and Ga, which have small reserves and are very expensive, are used as raw materials for the absorption layer. In addition, the method of thinning the absorption layer limits the degree of freedom or requires an additional process in color conversion because of the natural color of materials. In the case of laser etching, there are problems that reduce efficiency by causing laser damage, large area, and mass production. Focusing on the problems, this study intends to manufacture a transparent solar cell using the Cu2ZnSn(S,Se)4 (CZTSSe) thin-film solar cell, which is being studied to compensate for the CIGS raw material problem. In this dissertation, to increase the understanding and reliability of thin-film solar cell fabrication, the ratio of composition and effect of alkali doping on the absorber layer of CZTSSe thin-film solar cell was preceded. After then, photolithography was applied to make opening apertures for the transparency of the device. In addition, by placing an LED array in the opening that causes the loss of light conversion efficiency, the loss of PCE was compensated by an element with both a BIPV and an external display function. The manufactured mesh-type transparent solar cell confirmed 0.35 LUE (Light Utilization Efficiency) and 49.5% AVT (Average Visible Transmittance) about the entire cell area.