CHARACTERIZATION OF P TYPE A-SIC:H/C-SI HETEROJUNCTION SOLAR CELLS WITH THE INTRINSIC A-SI:H BUFFER LAYERS PREPARED BY ICP-CVD

摘要

We have fabricated the p type a-SiC:H/Crystalline Si solar cells with thin intrinsic a-Si:H bufferlayers using inductively coupled plasma chemical vapor deposition (ICP-CVD) method. Deposition process of a-Si:H flms was performed by varying the parameters, radio frequency (RF) power and substrate temperature, while aworking pressure was fixed at 70 mTorr. When the RF power and substrate temperature were 300 watt and 250°C,respectively, optical bandgap and photosensitivity, similar to the intrinsic a-Si:H film, were obtained. To investigatethe thickness effect of intrinsic a-Si:H film in heterojunction solar cells, These films were deposited in thicknessrange of 1～5nm onto the n-type Si wafer. A 12nm p type a-SiC:H films and 120nm Al doped ZnO(AZO, Al_2O_32wt% doping) was deposited by ICP-CVD and RF magnetron sputter, respectively. The thickness of i-a-Si:H thinlayer in the best performed solar cell was 3nm. Its conversion efficiency is 9.08% with Voc of 0.85V, FF of 0.271,and Jsc of 12.4mA/cm under the air mass (AM) 1.5 illumination from the front side. Quantum efficiency (QE)measurement on these solar cell shows over 90% in the region between 540nm and 780nm.