Effective utilization of light by transparent conducting oxide layer to enhance the performance of the silicon heterojunction solar cells

This article presents effective utilization of light by transparent conducting oxide (TCO) layer to enhance the performance of c-Si/a-Si:H heterojunction solar cells (HJSC) by simulation. The optical and recombination losses in solar cells severely deteriorate the short circuit density (Jsc), open circuit voltage (Voc) and then efficiency (η) of the solar cells. In order to reduce the optical losses, recombination losses and to improve the efficiency of solar cell devices, the c-Si/a-Si:H HJSC performance was investigated by planner and textured indium tin oxide (ITO) and zinc oxide (ZnO) layers as front TCO layer with AFORSHET simulations tool. Absorption and reflection spectra of ITO and ZnO layers were analysed separately before incorporating in to the c-Si/a-Si:H HJSC. The estimated solar cell parameter values of 763.7 mV, 40.96 mA cm−2, 85.91% and 26.86% correspond to Voc, Jsc, FF (fill factor) and η respectively for the cells with plane ZnO layers. It is found that the best values of Voc (763.7 mV), Jsc (41.87 mA cm−2), FF (85.91%) and η (27.47%) were obtained with textured ZnO layer. This is mainly due to reduced reflection losses and also increased absorption of photons in c-Si wafer with texturing of TCO layer, which results in increase of short circuit density of solar cells. The efficiency of solar cells with ITO is slightly lower than the ZnO layer.