Study of the effect of grading in composition on the performance of thin film solar cells based on AlGaAs and CZTSSe, a numerical simulation approach

Abstract

One of the promising methods to enhance the performance of third generation solar cells is to use compositionally graded layers. The aim of this work is to study the effect of grading in composition on the performance of solar cells based on AlGaAs and CZTSSe via numerical simulation with SCAPS 1D software. The gradient is simultaneously in the composition and in doping concentration. To attain this goal, we have optimized the uniform devices as a first step. Then, we have optimized the usual front, back, double and fully graded device. The most important observation in AlGaAs is that the open circuit-voltage Voc is much higher than that of with uniform composition. In the case of KS/ST-CZTSSe The effect of tow grading profile was investigated fully graded (a) and double graded (b). Cells with profile (a) has better parameters than all uniform kesterite and stannite cells. It was found that front grading has a destroying effect on solar cell parameters. In contrary, cell with profile (b) with only back grading ameliorates extremely the solar cell parameters. We showed that a grading strategy with fully graded device can indeed lead to more favorable trade-off between Jsc and Voc .