A Detailed Theoretical Analysis of TOPCon/TOPCore Solar Cells Based on p-type Wafers and Prognosticating the Device Performance on Thinner Wafers and Different Working Temperatures

In the present work, Automat FOR Simulation of HETerostructures (AFORS-HET v2.5) simulation software was used to investigate the performance of p-type tunnel oxide passivated contact (p-TOPCon) solar cells. Firstly, the influence of SiOx thickness on the device performance at different rear surface recombination velocity (SRV) was studied thoroughly; the same was followed by the incorporation of pinholes at different oxide thickness to realize the impact of pinhole density (D-ph) on the charge carrier transport mechanisms through the ultra-thin SiOx tunneling layer. Next, the doping concentration of p(+) poly-Si layer was varied to reveal its impact on the device output and it was noticed that presence of pinholes might facilitate the transformation of charge carriers through ultra-thin SiOx tunneling layer even at relatively lower poly-Si doping concentration. Furthermore, the consequence of wafer thickness at different wafer lifetime and at different front SRV on the performance of p-TOPCon solar cells was studied thoroughly. A relative analysis on the device performance in between the conventional TOPCon and TOPCore (TOPCon with p-type wafer and n(+) poly-Si as rear emitter) solar cell architecture based onto p-type base substrate was conducted. Eventually, an in-depth comparative analysis of the thermal stability among TOPCon, TOPCore and baseline BSF (back surface field) solar cells was carried out for both thicker and thinner wafers. The role of pinholes on the thermal stability of the devices was also pinpointed and it was yielded that our optimized device parameters might enable the best possible thermal stability along with higher power output.