限制高效Cu(In,Ga)2Se2光伏器件性能的微观机制的低温测试分析与模拟研究

The micro-mechanism becomes the bottleneck problem of performance improvement，when stable efficiency of CIGS thin film solar cell became above 15%. In view of the current lower fill factor and open circuit, this project intends to combine two Characteristic methods: low-temperature test technology (low-temperature hall, PL and I – V), professional simulation software wxAMPS. With key Cu element as the main clue, the defects distribution and interface tunneling mechanism will be further studied, and the more precise carrier transport model will be established, and explore the key science problem decreasing of the shunt resistance, open circuit voltage and fill factor. include: 1) the reaction mechanism of Cu element in three-step process; 2) defects distribution in different-content CIGS cells and formation mechanism of metastable characteristic; 3) interface tunneling mechanism and the interface of combination path in CIGS device of Cu-poor surface. 4) process optimization , improvement of defects and surface Cu distribution in order to stabilize and improve output characteristics of the device. The development of this project will not only enhance the understanding the basic research of CIGS solar cell, solve the key scientific problems，but also provide further testing and simulation methods for other thin film solar cell research.

CIGS薄膜太阳电池进入高效（稳定转换效率>15%)阶段后，其微观机制成为制约性能提升的瓶颈。针对目前电池填充因子、开路电压低的问题，本项目拟结合两种特色方法：一.低温测试分析技术（低温hall、低温PL谱、低温I-V）；二.新版专业仿真软件wxAMPS。以关键的Cu元素为主线，深入研究CIGS电池的缺陷态分布、界面遂穿机制，建立更确切的载流子输运模型，找出制约电池并联电阻、填充因子、开路电压的关键科学问题。主要内容包括：1）探索Cu元素在三步法中的反应机理；2）总结Cu含量对缺陷态的影响及亚稳态的形成机制； 3) 总结表面贫Cu结构的界面遂穿机制、界面复合路径。4）优化工艺，改善缺陷态分布、表面Cu元素分布结构，稳定器件性能，提升电池输出特性。本项目的开展将加深CIGS电池的基础研究，解决影响电池高效的关键科学问题，也为其他薄膜太阳电池的研究提供更深入的测试和仿真技术。

CIGS薄膜太阳电池进入高效阶段后，其微观机制成为制约性能提升的瓶颈。本课题针对CIGS太阳电池开路电压、串联电阻高的问题，利用共蒸发法制备了CIGS薄膜材料及电池器件，采用结构特性、光学特性、电学特性等多种表征手段（台阶仪、Hall测试、拉曼测试、分光光度计、SEM测试、X衍射、X荧光光谱分析等），结合低温测试分析技术（低温hall、低温I-V）和专业仿真软件wxAMPS两种特色方法。主要分析了：一、材料中Cu元素在CIGS中的生长机制，富Cu和贫Cu元素对CIGS材料和器件的影响。二、模拟结合测试分析了温度对CIGS微观机制及电池性能的影响。对解决电池开路电压低、串联电阻高的关键问题提供了有力证据，并对电池进行了优化研究。