基于辐射引入复合中心的GaAs三结太阳电池性能衰降分析

The project work will investigate the introduction rate k as well as the capture cross sections σ of recombination centers induced by proton and electron irradiation, a new analysis method of GaAs triple-junction solar cell degradation based on irradiation-induced recombination centers with the k and σ will be established. With helps of the data of proton and electron irradiation effects on the space solar cell measured using I-V characteristics and the k and σ in subcells obtained using optical exciting deep level transient spectroscopy (ODLTS) and photoluminescence (PL), and the relation of the solar cell degradation to k and σ derived from the semiconductor equation and the relation of minority carrier lifetime and the irradiation fluence, the irradiation induced degradation of the solar cell will be estimated, and compared with the experiment results. And as a result, the analysis method with k and σ will be verified to be effective and correct. If constant γ and nonionizing energy loss relative to irradiation damage are known by experiment and calculation, the introduction rate k of proton and electron irradiation with any one energy can be obtained on the fact that k is proportional to nonionizing energy loss, and then the degradation of the solar cell induced by proton and electron irradiation with any one energy may be forecasted using the analysis method with k and σ. At the same time, the analysis of k and σ associated to the irradiation damage mechanism may give a support to new solar cell designed. The research work will provide the information for irradiation resisting design and performance improving of new solar cell, and also give a new approach for predicting the degradation behavior of the solar cells in space application.

本项目将研究辐射损伤缺陷复合中心的引入率k和俘获截面σ，建立基于粒子辐射引入复合中心的GaAs三结太阳电池性能衰降分析方法。研究将利用电池质子、电子辐射实验数据和各子电池材料辐射损伤光致发光和光激发深能级瞬态谱测量，结合半导体方程和少子寿命与辐照通量关系推导的电池性能衰降与复合中心k及σ等参数之间的联系，分析电池性能衰降；并与电池性能衰降实验结果进行比较，验证复合中心kσ预估分析方法的有效性和正确性。探索实验方法确定与辐射损伤有关常数γ，计算非电离能损，利用k与非电离能损的正比关系获得任一能量粒子辐射对应的引入率k，用kσ预测方法分析可预估任一能量粒子辐射电池引起的衰降；分析k和σ等物理参数探索电池辐射损伤机理为更长寿命新电池研发提供支持。本项目研究不仅可为预测空间三结电池性能衰降和工作寿命提供简便、经济、快速的全新分析方法，而且也可为更长寿命太阳电池设计研发及抗辐射加固筛选提供科学依据。

为了卫星等航天器任务的顺利完成，须要预测卫星上太阳电池性能衰降和工作寿命，也须要长寿命太阳电池设计研发及抗辐射加固筛选。因此，本项目重点开展了辐射损伤缺陷复合中心的引入率k和俘获截面σ，基于粒子辐射引入复合中心的GaAs三结太阳电池性能衰降分析方法研究。研究利用半导体方程和少子寿命与辐照通量关系，推导出GaIn P子电池和GaAs子电池Jsc、Voc衰降与复合中心参数等联系式, 结合卫星用国产新型GaInP/GaAs/Ge三结太阳电池质子、电子辐照效应数据，可评估这种新型电池的抗辐射性能和预测其工作寿命；实验用电致发光谱（EL）和光致发光谱（PL）测得GaInP和GaAs子电池的复合中心参数值，可用其参数探索分析太阳电池辐射损伤微观机理，分析确定位于价带以上0.55 eV的H2空穴缺陷是非辐射复合中心，是导致GaInP子电池性能衰降的本质原因；而对于GaAs太阳电池，可确定非辐射复合中心对应于导带下0.58 eV的E5电子陷阱是导致其性能衰降的主要原因。研究结果得到的分析方法可预估任一能量粒子辐射电池引起的衰降，为预测空间三结电池性能衰降和工作寿命提供了分析方法；用光（电）致发光谱测得的各子电池kσ、k及σ值分析太阳电池辐射损伤微观机理，为更长寿命太阳电池设计研发及抗辐射加固筛选提供了参考依据。