SiOx/polysilicon selective emitter prepared by PECVD-deposited amorphous silicon plus one-step firing enabling excellent J0,met of < 235 fA/cm2 and & rho;c of < 2 m & omega;& BULL;cm2

Boron(B)-doped polysilicon (poly-Si) is the key element to achieve high efficiency and low-cost bifacial tunnel oxide passivated contact (TOPCon) silicon solar cells. In this work, we explore the feasibility of using a plasma -enhanced chemical vapor deposition (PECVD) system to prepare the high-performance poly-Si fingers as selec-tive emitters (poly-finger SE) through depositing nano SiOx and B-doped amorphous silicon plus one-step annealing process. It is found that the poly-finger SE not only reduces the recombination current density under metal contacts (J0,met) from -1300 fA/cm2 to -230 fA/cm2, while maintaining a low contact resistivity (& rho;c) of -1.6 m & omega;& BULL;cm2. Additionally, numerical simulations indicate that n-type Si solar cells with poly-finger SE can achieve a high efficiency of 25.36% based on the most advanced device manufacturing technology and the above-mentioned passivation and contact performances. The open-circuit voltage (Voc) increased by 11.1 mV and 4.8 mV compared to controlled and laser SE TOPCon solar cells, manifesting the efficiency increase of 0.39% and 0.20%. Overall, this work presents a new method to enhance the efficiency of TOPCon devices.