质子辐射损伤对单结GaAs/Ge太阳电池暗特性参数的影响

基于p-n结暗特性双指数模型,对经质子辐射后的单结GaAs/Ge太阳电池的暗特性I-V曲线进行数值拟合,确定了单结GaAs/Ge太阳电池在辐射前后的四个暗特性特征参数,即串联电阻R_s、并联电阻R_(sh)、扩散电流I_(s1)和复合电流I_(s2).研究结果表明,质子辐射后单结GaAs/Ge太阳电池的R_s,R_(sh),I_(s1)和I_(s2)四个暗特性参数均发生显著变化.经低能质子辐射后,单结GaAs/Ge太阳电池的R_(sh)随位移损伤剂量的增加而减小,而R_s,I_(s1)和I_(s2)三个参数随位移损伤剂量的增加而增大,其中串联电阻随位移损伤剂量线性增加而与辐射质子能量无关.理论分析表明,上述参数的变化与质子辐射损伤区域分布有关.基区和发射区的损伤主要引起单结电池串联电阻和扩散电流的增加;结区的损伤导致并联电阻减小,复合电流增大.

Effect of irradiation damage on the dark electric properties of single junction GaAs/Ge solar cells

In this paper, the dark electrical properties are studied by measuring the dark current-voltage characteristics of a type of domestic single-junction (SJ) GaAs/Ge solar cell after proton irradiation. Using a double exponential mode for the dark electrical properties of p-n junction, the dark I-V curves of the proton-irradiated SJ cells are mathematically fitted, and there are four kinds of typical parameters, namely serious resistance (R_s), parallel resistance (R_sh), diffusion current (I_s1), and recombination current (I_s2), which are determined to characterize the irradiation effects. Hence, four parameters such as R_s, R_sh, I_s1 and I_s2 are significantly changed after proton irradiation, where R_s, R_sh, I_s1 increase while R_sh decreases with increasing the displacement damage dose. In addition, R_{s } increases with displacement damage dose, which is unrelated to proton energies. Theoretical analysis indicates that the above-mentioned changes of the parameters result from the damage distributions in different regions of the solar cells. Irradiation-induced damage in the base and emitter regions of the cells could induce R_s and I_s1 to augment, while junction-region damage causes the R_sh to decrease but the I_s2 to increase.
Keywords： GaAs/Ge solar cells proton irradiation dark electric properties numerical fitting