Current status and future prospect for thin film silicon based photovoltaic module manufacturing technology at Hanergy

We report the recent progress in the development of a-Si/a-SiGe and a-Si/nc-Si multijunction solar cells on the product size substrate of 0.79m², and heterojunction solar cells on 152.3cm² n-type silicon wafer at Hanergy. Main experimental results cover three aspects: (a) for a-Si/a-SiGe multijunction solar cells, significant improvement in a-Si/a-SiGe triple junction PV module efficiency by optimizing a-Si and a-SiGe component cell performance, (b) for a-Si/nc-Si double junction solar cells, optimization of a-Si thin film and doped layer/buffer layer used for a-Si top cells, and device quality nc-Si bottom cells , and (c) for heterojunction solar cell, development of intrinsic a-Si for superior silicon wafer surface passivation, wafer surface texturing process, n-type a-Si thin films as window layers, and ITO layers. We attained 11% initial total area efficiency for a-Si/a-SiGe triple junction modules, and 12.8% initial total area efficiency for a-Si/nc-Si double junction modules, and 21.7% total area efficiency for heterojunction solar cells using n-type wafers.