倒置生长晶格失配四结（IMM4J）太阳电池辐射损伤缺陷动态演化机制研究

Due to graet requirements for space solar cell with high efficiency and power/mass ration and developed micro-electronics technology, it spurs fast development of multi-junction solar cell using inverted epitaxial technology. Presently, it is getting matured to fabricate some kind of inverted metamorphic III-V group 4-junction solar cells (IMM4J). Based on the space application requirements, we will systematically investigate the annealing effects of the electrical properties and photoelectric conversion behavior of the two low-gap lattice mismatch InxGa1-xAs sub-cells of the IMM4J solar cell. In this project, irradiated defects in InxGa1-xAs sub-cells will be focused on their formation, corresponding evolution processes and dynamic evolution machanism under different annealing temperature and time using complementary analytical methods such as deep level transient spectrum (DLTS), positron annihilation life spectrum (PALS) et. al. All of the investigated results would provide technical and theoretical support to improve the properties of the IMM4J cells in terms of materials selection, gap modifications, manufacture process optimizing, safe and reliable services on-orbit.

高效、轻质空间电源需求及先进微电子制造技术催生了倒置生长晶格失配多结太阳电池的快速发展，目前倒置III-V族四结太阳电池（简称IMM4J电池）的制备工艺已经基本成熟。本项目针对新型高效IMM四结太阳电池的空间应用需求，以IMM4J电池的两结关键的晶格失配低带隙InxGa1-xAs子电池为研究对象，首先研究带电粒子辐照后电池电性能、光电转换行为的退火恢复规律；再利用深能级瞬态谱（DLTS）、正电子湮灭寿命谱（PALS）等测试手段重点研究了两结InxGa1-xAs子电池的辐照损伤缺陷状态、分析缺陷对电池电性能影响的演化规律，以及不同温度和时间退火条件下缺陷能级的动态演化机制，为空间太阳电池的选材、带隙调整、工艺优化及在轨可靠服役提供技术支持和改进方向。

本项目是以GaInP(1.89eV)/GaAs(1.41eV)/In0.3Ga0.7As(1.0eV)/ In0.58Ga0.42As (0.7eV)倒置四结电池的两种InxGa1-xAs关键子电池为研究对象，基于不同种类及能量的带电粒子辐照试验和退火试验，深入进行位移辐射深能级缺陷诱导空间太阳电池性能退化机理研究。主要研究内容包括：.(1)带电粒子辐照InxGa1-xAs子电池(带隙为1.0eV和0.7eV，x=0.3和0.58)后其原生缺陷和辐射损伤缺陷演化的基本特征；.(2)带电粒子辐照两种InxGa1-xAs子电池后，在其服役工作温度下的退火效应及其电性能（Voc，Isc和Pmax）恢复规律；.(3)带电粒子辐照两种InxGa1-xAs子电池后，不同退火温度和时间条件下辐射损伤缺陷演化特征与物理机制。.本项目完全按申请书中计划进行，按照进度要求到2021年12月，已经完成了项目申请书所规定的全部研究内容，实现了研究目标。