碳离子辐射对空间GaAs/Ge太阳电池性能影响的研究

Carbon ion irradiation effects on GaAs/Ge solar cells

利用2×1.7 MV串列静电加速器提供的碳(C)离子束模拟空间环境辐射,对空间GaAs/Ge太阳电池用注量为3.1×109—6.9×1012 cm-2的2 MeV C离子进行辐照。通过I-V特性和光谱响应测试,研究分析了GaAs/Ge太阳电池的C离子辐射效应。结果表明:随着C离子辐照注量的增加,GaAs/Ge太阳电池电性能参数Isc、Voc和Pmax衰降增大,其中Pmax衰降最大,Isc次之,Voc最小。该衰降规律和质子辐照的衰降规律相似。但使GaAs/Ge太阳电池的Pmax衰降到原值的50%,用C离子辐照所需注量要比相同射程的质子辐照小两个量级。在低注量辐照时,光谱响应衰降主要发生在长波范围;而注量大于3.1×1010 cm-2时,则发生明显的长、短波整个波段的光谱响应衰降;当注量增大到2.3×1011 cm-2以上,光谱响应基本消失。

For simulating space environmental radiation a 2×1.7 MV tandem accelerator was used. GaAs/Ge solar cells were irradiated using 2 MeV C ions with the fluence from 3.1×10^9 to 6.9×10^12 cm^-2. Both Ⅰ-Ⅴ characteristics and spectral response were measured before and after irradiation. The results show that the Isc, Voc and Pmax of GaAs/Ge solar cells decrease as the irradiation fluence increases, and among them, Pmax decreases the most while Voc the least. This degradation rule is similar to that induced by proton irradiation. But to make Pmax of GaAs/Ge solar cells decrease to 50%, the required irradiation fluence of C ion is less than that of proton with the same range by two orders of magnitude. The spectral response of GaAs/Ge solar cells decreases more significantly in the long wavelength region than in the short wavelength region after C ion irradiation at a low fluence of 3.1×10^9 cm^-2. When the fluence increases to more than 3.1 ×10^10 cm^-2, the spectral response in the whole wavelength region significantly degrades. As the fluence reaches to 2.3×10^11 cm^-2, the spectral response disappears.