飞秒激光辐照对GaAs/Ge太阳能电池的性能退化研究

Property Degradation of Ga As/Ge Solar Cells after Femtosecond Laser Irradiation

研究了飞秒激光辐照对Ga As/Ge太阳能电池的损伤效应,利用光学显微镜和非接触光学轮廓仪表征电池表面损伤形貌,并用伏安特性测试系统表征电池辐照前后的光伏特性。分析了不同激光能量密度下,激光烧蚀对电池表面形貌及电学性能产生的损伤程度。实验结果表明,激光能量密度小于0.53 J/cm2时,仅损伤到减反射膜;随激光能量密度的增加,电池损伤深度不断增加,当能量密度为0.78 J/cm2时,已损伤到电池发射区;电池性能参数如短路电流、开路电压、最大功率和填充因子随激光能量密度的增加而衰减,衰减幅度先增加后减小;在所有测试参数中,光电转化率的退化最为明显。飞秒激光辐照对太阳能电池具有破坏性的影响,这直接影响到电池的光伏特性。

Effects of femtosecond laser irradiation on GaAs/Ge solar cells are studied. Optical microscope and noncontact optical profllometer are used to measure the surface morphology of the solar cells and the the volt-ampere characteristic test system is used to test the photovoltaic properties. The damage degree of ablation on the surface morphology and electrical properties is analysed. The results indicate that when the laser energy density is below 0.53 J/cm^2, the damage only reaches the anti-reflection film. With the increase of laser energy density, the damage depth of the solar cell is increasing, when the laser energy density reaches 0.78 J/cm^2, the damage gets to the emitter region. With the density increasing, the electric properties such as short circuit current, open circuit voltage, maximum power and filling factor suffer a certain degradation. The decay amplitude of the electric properties increase at first and then decrease. Among all the evaluated electric properties, maximum power degrades most remarkably. In conclusion, laser irradiation could induce a great damage in GaAs/Ge solar cells, which influences the electric properties directly.