电势诱导衰退和湿热衰退P-PERC太阳能电池的修复与增效

针对P型钝化发射极背面接触(PERC)太阳能电池在服役期间受到电势衰退和湿热诱导衰退影响而引起光电转换效率降低的问题,本文通过光电注入和热退火工艺对已衰退电池进行修复并研究其增效机制。实验结果表明:在光照强度为3倍标准太阳光、电注入电流为10 A、退火温度为150 ℃、工艺50 min实验条件下,对180片已衰退电池进行修复实验,其中94.32%的已衰退电池的光电转换效率得到修复,实验后电池光电转换效率平均提升8.96%。光致发光光谱和量子效率分析表明,光电注入和热退火工艺可有效减少电池因电势诱导衰退和湿热衰退形成的内部缺陷和背表面缺陷,提升衰退电池片的光电转换效率。

Recovering and Efficiency Improvement on Potential Induced and Damp Heat Degradation of P-PERC Solar Cells

In view of the problem that the photoelectric conversion efficiency of P-type passivated emitter rear contact (PERC) solar cells reduces due to the influence of potential induced degradation and damp-heat degradation during the service period, the degraded solar cells were recovered by photo & electric injection and thermal annealing process. In the meantime, the efficiency improvement mechanism was studied. The experimental results show that 94.32% of degraded solar cells are recovered successfully, and the average photoelectric conversion efficiency of all investigated cells is increased by 8.96%, under the optimal experimental conditions of 3 times standard sunlight intensity, 10 A of electric injection current, 150 ℃ of annealing temperature, and 50 min of processing. The results of photoluminescence spectra and quantum efficiency show that the photoelectric injection and thermal annealing can effectively reduce the internal and rear surface defects of silicon substrate caused by potential induced degradation and damp-heat degradation, and the photoelectric conversion efficiency of degraded solar cells can be finally improved.