Comparison of intrinsic amorphous silicon buffer layers for silicon heterojunction solar cells deposited with different PECVD techniques

In this investigation we compare intrinsic hydrogen diluted amorphous a-Si:H(i) layers deposited by inductively coupled plasma (ICP) to the standard parallel plate (PP) plasma, driven by 13.5 MHz power source. We analyze and compare the growth rate, optical energy gap, homogeneity, passivation quality, and most importantly silicon heterojunction solar cell performance. The ICP a-Si:H(i) layer shows superior properties regarding the growth rate, however, we obtain a slightly better passivation quality with the PP a-Si:H(i) layer, with V_oc values up to 723 mV. Looking at the overall solar cell performance we were not able to see any difference between ICP and PP silicon heterojunction solar cell. The best solar cell (with an ICP a-Si:H(i) layer) has an efficiency of 18.7%.