Novel Passivation and Gettering Strategy for Silicon Wafer by Al2O3/n-poly-Si/SiOx Stack for High-Efficiency p-Type Passivating Tunnel Oxide Contact Solar Cells

This study focuses on the enhanced passivation and gettering of boron-doped p-type solar grade silicon wafers by incorporating carrier-selective and passivating tunnel oxide contact (TOPCon). A symmetrical stack of aluminum oxide (Al2O3)/p-doped n-type polysilicon (n-poly-Si)/ ultrathin silicon oxide (SiOx) in conjunction with long cycles of forming gas annealing is used for enhancing the silicon wafer quality with a novel approach. Multilayer of n-poly-Si/SiOx on p-type crystalline silicon wafer exhibits an implied open-circuit voltage (iV(oc)) of 726 mV, effective carrier lifetime (tau(eff)) of 857 mu s, and a low recombination current density (J(o)) of 1.9 fA cm(-2) when subjected to a postdeposition annealing (PDA) of phosphorus-doped hydrogenated amorphous silicon (n-a-Si:H) at 820 degrees C. To boost passivation and gettering quality, 10 nm-thick Al2O3 layers on both sides of n-poly-Si/SiOx samples are added. This leads to improved tau(eff) (962 mu s), reduced J(o) (1.1 fA cm(-2)), and higher iV(oc) (728 mV). Herein, a thinner 50 nm n-poly-Si layer for improved properties is applied. The experiments show improved passivation and gettering. A Quokka-3 simulation examines the potential of high-efficiency p-type TOPCon cells. A novel solar-grade p-type wafer quality enhancement approach is introduced, amalgamated with Quokka-3 results, which could be a milestone in high-efficiency p-type TOPCon solar cell production.