利用不同电压下的电致发光和红外热成像技术检测太阳能电池的缺陷。正向电致发光为电子空穴的辐射复合, 与太阳能电池的串联电阻和少数载流子扩散长度有关, 可以检测太阳能电池的断栅、隐裂等缺陷;反向电致发光为高电场强度下载流子的带内发光, 可以探测弱的线性漏电和击穿, 并且弱的线性漏电只在高的反向偏压下发光。利用不同电压下的红外热成像可以检测出线性和非线性漏电, 强线性漏电在正反偏压电压下均有明显发热的现象, 而非线性漏电在何种偏压状态下占优势取决于漏电类型。红外热成像无法探测出第二类击穿和第三类击穿。

The electroluminescence and infrared thermography were used to detect the defects of the solar cells by applying different forward bias and reverse bias voltage. The solar cell under forward bias mainly emits infrared light from 850 to 1 200 nm due to the recombination of electron and hole. The intensity of the emitted light depends on the series resistance and minority carrier diffusion length of the solar cell, so it can be used to detect the defects of finger disturbing, crack, and electrode etching, et al. The emission of light under reverse bias is intra-band emission which covers a wide spectrum from visible light to IR. The breakdown can be detected by reverse bias electroluminescence (RBEL). Only under high bias, weak Ohmic shunt appears in RBEL. Linear and nonlinear shunt can be detected using IR thermography under different bias. Strong Ohimc shunt can be detected in forward and reverse bias. The nonlinear shunt depends on the type.