Improvement of polymorphous/crystalline heterojunction solar cells using low temperature screen-printed pastes

An alternative way to conventional solar cell process is to develop a low temperature process using hydrogenated amorphous silicon (a-Si:H) thin film deposited by PECVD on bulk crystalline silicon. The French national project "SiNERGIES" aims to improve polymorphous/crystalline heterojunction (a-Si:H/pm-Si:H/c-Si) on p-type crystalline silicon (c-Si) to achieve large area solar cells for industrial application. We present the advancement of the project, focusing on low temperature screen-printed pastes (LT-SP) as well as the analysis of the pm-Si:H/c-Si interface quality. Up to now, solar cells of 25 cm/sup 2/ area using CZ (Si) substrate achieved efficiency close to 13.5% with a maximum fill factor of 70% with LT-SP from Dupont MCM. A simulation study gives insight into the possible improvements.