Boron Doping Technology for the Front Polysilicon Layer of Full TOPCon Cells

Abstract

Abstract: In order to improve the efficiency of tunneling oxide passivated contact (TOPCon) cells, a p-type tunneling oxide passivation contact structure was fabricated on the front of N-type TOPCon cells through high-temperature diffusion, improving the emitter passivation performance and reducing front metal recombination. The effects of different deposition time, drive-in temperature, drive-in time and other process parameters on the passivation performance and doping curve of experimental samples were investigated. The experimental results show that when the deposition time is 1 500 s, the drive-in temperature is 920 ℃, and the drive-in time is 20 min, the boron doped polysilicon layer can achieve better passivation performance and boron doping concentration, with the doping concentration of sample polycrystalline silicon layer reaching 1.40×10²⁰ cm^-3. The implied open circuit voltage(iV_oc) is greater than 720.0 mV. The photoelectric conversion efficiency of TOPCon cells prepared based on this parameter can reach 23.89%, corresponding to a short-circuit current density of 39.36 mA/cm², the open circuit voltage (V_oc) is 726.4 mV, and the fill factor (FF) is 83.54%

Key words: TOPCon cell, tunnel oxide passivation contact, boron diffusion, passivation, current density, photoelectric conversion efficiency

CLC Number:

TM914.4

ZHANG Bo, SONG Zhicheng, NI Yufeng, WEI Kaifeng. Boron Doping Technology for the Front Polysilicon Layer of Full TOPCon Cells[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(2): 329-335.

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