Influence of injection level and wafer resistivity on series resistance of silicon heterojunction solar cells

International audienceChoice of topic: This work focuses on the modeling and characterization of silicon heterojunction solar cells. Scientific innovation and relevance: Series resistance (R S) in SHJ cells is related to various carrier transport mechanisms in both bulk materials and at the interfaces, in combined transverse and lateral directions. We propose to review the influence of wafer dark resistivity on R S of SHJ cells with the rear emitter configuration and propose a new approach for improved modeling of such devices. Aim and approach used: Our work aims at improving understanding and modeling of R S various contributions in SHJ cells with rear emitter configuration. For this purpose, we prepared rear emitter n-type SHJ cells varying the substrate dark resistivity from 0.49 to 14.1 Ω. cm, as well as special samples to allow the measurement of electron contact resistance (ρ C,e −). We examined variations of effective lifetime, efficiency and series resistance with c-Si dark resistivity. Results: Efficiency varies only slightly with wafer dark resistivity in our experiment. Injection level is found to be very important to examine performance, both for passivation and series resistance matters. We propose a series resistance model that takes into account the lateral transport in parallel between the c-Si wafer and the ITO layer under varying injection levels