Research Of Porous GaAs Light Trapping Layer For Solar Cells

Solar as a new clean energy is much more important. Solar cells as a important part of solar, the research of solar cells make a lot of results. Many semiconductor materials as solar cell materials have been researched. There is high efficiency, good temperature characteristics and anti-radiation in GaAs solar cells, so GaAs solar cells is a good space solar cells. Factors affecting the efficiency of solar cells are mainly concentrated in two areas of optical loss and electrical loss. Therefore, an effective light trapping layer is indispensable to achieve high efficiency design.In this paper, the porous GaAs light trapping layer was prepared by electrochemical etching method. In order to get the high quality porous layer, the preparation conditions of Porous GaAs light trapping layer were optimized by changing the etching voltage, solution concentration. Surface morphology and etching mechanism were analyzed by SEM in this paper and the same time the reflection spectrum of the samples prepared under different etching conditions were invested by used the reflection spectrum measurement system. Anti-reflection model was set up and the optimal etching conditions were got Through the results obtained the best etching conditions in the different solutions, The best etching conditions was obtained in hydrochloric acid and hydrofluoric acid. For1200seconds, the best etching current was0.5mA in0.1M hydrochloric acid, the best etching current was3mA-10mA in hydrofluoric acid, the best etching current was10mA in mixed solution of hydrochloric acid and hydrofluoric acid. To further study the porous GaAs layer surface electrical properties, the structure of Au/porous GaAs was prepared. The characteristics of current-voltage and capacitance-voltage were invested by used I-V and C-V measurement system. The parameters of ideality factor, series resistance, and trap level density of the Au/porous GaAs Schottky structure were calculated. And then the experience in the direction of the porous GaAs light trapping layer improve the efficiency of solar cells...