High-Efficiency HIT Solar Cell on Thin (<100 μm) Silicon Wafer

Abstract

In order to reduce the power-generating cost of a silicon solar cell, it is necessary to use a thinner crystalline silicon (c-Si) wafer together with the excellent light trapping and well passivated surface that are essential for high-efficiency solar cells. The HIT (Heterojunction with Intrinsic Thin-layer) solar cell is an amorphous silicon (a-Si)/c-Si heterojunction solar cell that has these features. We have experimentally confirmed that the Voc of the HIT solar cell increased with decreases in the cell thickness and can reach more than 0.74 V. This indicates that the surface recombination velocity of the HIT structure is extremely low due to excellent passivation on the c-Si surface. A conversion efficiency of 22.8 % has been achieved with a 98-μm thick CZ c-Si (100.3-cm2) cell.