Enhancing industrialization TOPCon solar cell efficiency via comprehensive anti-reflection passivation film optimization

This study focuses on enhancing the performance of n-type Tunnel Oxide Passivated Contact (TOPCon) solar cells by exploring the optimization of both front and rear film layers. For the front film, we implement a one-step plasma oxidation process before depositing silicon nitride on alumina, aiming to enhance the quality of the alumina layer and improve overall passivation. In the case of the rear film, we introduce a NH3 plasma treatment to elevate hydrogen content of SiNx. These additional hydrogens diffuse into the interfacial silicon oxide during the firing process to help reduce the number of surface dangling bonds and inhibit the degradation of the passivating contacts, which significantly contributes to enhanced passivation quality. Through separate optimization of these film layers, we aim to harness the full potential of TOPCon solar cells, achieving remarkable improvements in passivation quality and overall performance. With the help of XRD, SIMS, QSSPC, ellipsometry and other characterization tools, the underlying reasons for the improved passivation quality due to plasma oxidation and plasma hydrogenation were explored. Finally, plasma oxidation and hydrogenation lead to ∼0.06 and ∼0.07% average efficiency enhancements, respectively.