100keV质子辐照对空间GaAs/Ge太阳电池光电效应的影响

Effect of 100keV proton irradiation on photoemission of GaAs/Ge space solar cells

利用空间环境模拟设备,用固定能量为100keV、注量为1×109—3×1012cm-2的质子,对空间实用GaAs/Ge太阳电池进行了辐照试验.利用伏安(I-V)特性、光谱响应和光致发光(PL)光谱测试,研究分析了电池的光电效应.试验表明,电池的各种电性能参数如短路电流(Isc)、开路电压(Voc)、最大输出功率(Pm)和填充因子(FF)都因质子辐照注量的增加,出现不同程度的衰降.在质子能量相同条件下,电池电性能衰降均随照射注量增大而增大.质子辐照对材料的光电性能具有破坏性的影响.这种破坏性是由于质子辐照引入的大量缺陷,使晶格空间的完整性受到破坏,导致少子的扩散长度降低、表面复合速度增加所致.

The experiment of GaAs/Ge solar cells co-irradiated by proton and electron was done in space environment simulation equipment.The materials of GaAs/Ge solar cell are irradiated by proton beam with fixed energy of 100keV and dose from 1×109 to 3×10 12 cm -2.The I-V characteristic,spectral response and photoluminescence（PL） spectra were measured before and after irradiation in order to study the cell＇s performance degradation induced by irradiation.The result indicated that the parameters such as short circuit current（I_ sc）,open circuit voltage（V_ oc）,maximum output power（P_ max） and fill factor（FF） all suffer degradation at different degrees as the irradiation fluence increases.The results show that proton irradiation induces a great damage in optical characteristics of the solar cell,resulting from the large quantity of irradiation defects that would destroy crystal lattice integrity and reduce the diffusion distance of minority carrier,and thus increase the surface recombination velocity.The damage extent of GaAs/Ge solar cell increases with proton dose in the ranges under investigation.