Surface passivation and heterojunction cells on Si (100) and (111) wafers using dc and rf plasma deposited Si:H thin films

The structure of hydrogenated silicon (Si:H) films deposited by rf and dc plasma process on Si (100) and (111) wafers is correlated with the surface passivation quality and heterojunction cell performance. Microstructural defects associated with SiH2 bonding and apparent ion bombardment in dc plasmas have little or no adverse effect on passivation or cell properties, while presence of crystallinity in Si:H i layer severely deteriorates surface passivation and cell open circuit voltage (V-oc). Excellent surface passivation (lifetime of >1 ms) and high efficiency cells (>18%) with V-oc of 694 mV are demonstrated on n-type textured Czochralski wafer using dc plasma process. (C) 2008 American Institute of Physics.