Theoretical investigation of transparent front surface field layer on the performance of heterojunction silicon solar cell

Abstract

In order to couple more light in absorber layer of a silicon heterojunction (SHJ) solar cell, higher optical transparency of the front layer is desirable. In that respect we investigated indium tin oxide (ITO) as a front surface field (FSF) layer in a rear emitter SHJ solar cell. We used numerical simulation starting from an experimentally obtained real solar cell. In the experimental cell the n-type nanocrystalline silicon (n-ncSi:H) was used as the FSF, where the power conversion efficiency (PCE) of the reference cell was 21.84%. Our investigation shows that if 20 nm thick ITO is used as the FSF, the PCE of the device can be 25.67%, while with an 80 nm thick ITO as FSF, the PCE can be 23.8%. This improvement in the device efficiency primarily comes with the increase in current density in the solar cell due to an increased intensity of light in the absorber layer.