Optimization of Si (core)/CZTS/ CZTSe (shell) nanowire array for solar cell

Abstract We present an optical simulation of a solar cell employing core (Si) /shell (CZTS or/and CZTSe) vertically-aligned nanowire array. The method of the simulation is rigorous coupled wave analysis. In the first stage, we studied the case where the shell is composed of only CZTS or CZTSe. A larger absorption of CZTSe led to a larger value of the ideal short circuit current (41 mA/cm2) in the case of CZTSe solar cell than in the case of CZTS solar cell (24 mA/cm2). In the second stage, to avoid the heat losses in CZTSe solar cell without reducing the current, we proposed a shell composed of a 3µm of CZTS in the upper part and a 6µm of CZTSe in the lower part. The maximum ideal current value in this structure is almost twice as large as that of a planar solar cell with the same amounts of used materials.