Large Area TOPCon Cells Realized by a PECVD Tube Process

TOPCon is an appealing choice for next-generation solar cells as it minimizes surface recombination, enables low contact resistivities, and provides high thermal stability thereby rendering it compatible with screen-printed metallization. While TOPCon is commonly realized by low-pressure chemical vapor deposition (LPCVD), this paper discusses the use of a plasma-enhanced chemical vapor deposition (PECVD) tool, which are commonly used for deposition of SiNx or AlOx. It will be shown that thick screen-printing compatible TOPCon layers providing excellent surface passivation can be realized with such tool. Additionally, the firing stability of TOPCon/SiNx stack will be discussed and first solar cell results will be presented. The IV parameters of the best solar cell were: Voc = 691.2 mV, FF = 80.7%, Jsc = 40.4 mA/cm², and = 22.5%.