Industrial TOPCon Solar Cells realized by a PECVD Tube Process
These days low-pressure chemical vapor deposition (LPCVD) is commonly used by the photovoltaic industry to deposit Si layers for tunnel oxide passivated contact (TOPCon). This work summarizes the development of an alternative TOPCon deposition process using a tube plasma-enhanced chemical vapor deposition (PECVD) tool. In the first part, the main results of the German federal project ""Upgrade Si-PV"" are summarized. The goal of this project was the transfer of the TOPCon process to an industrial-proven tube PECVD system. In the second part, recent progress on the implementation of this process into a TOPCon cell is presented. It is demonstrated that the PECVD system is capable of producing screen-printing compatible TOPCon layers yielding recombination currents of ≈ 3 fA/cm² and ≈ 200 fA/cm² in the passivated and metallized region, respectively. The best TOPCon cell which was realized with the PECVD process yielded the following current-voltage parameters: Voc = 700 mV, FF = 79.6%, Jsc = 41.2 mA/cm², and = 22.95%.