TOPCon太阳能电池选择性发射极工艺研究

摘要/Abstract

摘要： 为提升隧穿氧化钝化接触(TOPCon)太阳能电池的光电转换效率,采用硼扩散和激光掺杂的方式形成选择性发射极结构,研究了硼扩散方阻、激光功率输出比、氧化时间等对电池发射极钝化性能的影响。实验结果表明,当扩散方阻为140 Ω/□,氧化温度为1 020 ℃,氧化时间为30 min时,发射极轻掺杂区域(p⁺)的方块电阻为320 Ω/□,隐开路电压值达到729 mV,暗饱和电流密度为12 fA/cm²。发射极重掺杂区域(p⁺⁺)的方块电阻为113 Ω/□,隐开路电压值为710 mV,暗饱和电流密度为26 fA/cm²。基于该工艺方案制备的TOPCon电池最高光电转换效率达到24.75%,电池开路电压高达720 mV,短路电流提升30 mA,相比现有TOPCon电池光电转换效率提升了0.26个百分点。

关键词: TOPCon太阳能电池, 选择性发射极, 硼扩散, 激光, 氧化, 光电转化效率

Abstract: In order to improve the photoelectric conversion efficiency of tunnel oxide passivated contact (TOPCon) solar cells, the selective emitter structure was prepared by boron diffusion and laser doping. The effects of sheet resistance of boron diffusion, power output ratio of laser and oxidation time on the passivation of the emitter were studied. The experimental results show that when the sheet resistance is 140 Ω/□, the oxidation temperature is 1 020 ℃, and the oxidation time is 30 min, the sheet resistance of light doping region (p⁺) reaches 320 Ω/□, the corresponding implied open circuit voltage reaches 729 mV, and the dark saturation current density is 12 fA/cm². The sheet resistance of heavily doping region (p⁺⁺) reaches 113 Ω/□, the corresponding implied open circuit voltage reaches 710 mV, and the dark saturation current density is 26 fA/cm². Based on the selective emitter process, the highest conversion efficiency of 24.75% was obtained with an open circuit voltage of 720 mV, and a short-circuit current improvement of 30 mA, leading to an absolute efficiency gain of 0.26 percent point for the champion conversion efficiency.

Key words: TOPCon solar cell, selective emitter, boron diffusion, laser, oxidation, photoelectric conversion efficiency

中图分类号:

TM914.4

杨露, 宋志成, 倪玉凤, 张婷, 魏凯峰, 阮妙, 石惠君, 郑磊杰. TOPCon太阳能电池选择性发射极工艺研究[J]. 人工晶体学报, 2024, 53(1): 138-144.

YANG Lu, SONG Zhicheng, NI Yufeng, ZHANG Ting, WEI Kaifeng, RUAN Miao, SHI Huijun, ZHENG Leijie. Process Study on Selective Emitter of TOPCon Solar Cells[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(1): 138-144.

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