单结GaAs太阳电池连续激光辐照热损伤机理

Thermal damage mechanism of single junction GaAs solar cells irradiated by continuous wave laser

开展了单结GaAs太阳电池808 nm、10.6μm连续激光辐照实验研究,结果显示,相同激光耦合强度下两种激光对电池的损伤模式相似,且随着激光耦合强度逐渐提高,电池最大输出功率呈现"阶梯"状下降。通过对比辐照过程中温升速率、温度峰值以及高温持续时间对损伤结果的影响,结合能谱仪和扫描电子显微镜的测量结果以及方差分析结果对损伤机理进行了分析和验证。认为高温导致GaAs分解、电极氧化是单结GaAs太阳电池性能退化的主因。

Single junction GaAs solar cells were irradiated by 808 nm and 10.6 μm continuous wave lasers respectively. The results show that, as long as under the same laser coupling intensity, the damage modes of solar cells under two different irradiation conditions are similar. As the laser coupling intensity increases, the maximum output-power of solar cells shows a ′ stair-step′ decline. Damage processes was further investigated through analysis of temperature rising rate, peak temperature, duration of high temperature and variance, as well as energy disperse spectroscopy and scanning electron microscope measurements. It is found that the high temperature during irradiation process leads to the dissociation of GaAs and the oxidation of the electrodes, which further results in performance degradation of single junction solar cells.