新型硅纳微米结构背接触太阳电池物理与器件研究

The investigation of physical properties and device application of novel solar cells is the frontier of modern condensed matter physics. This project proposes the basic research of silicon based solar cells with nano/micro structure and back contact. By the combination of the optical advantage from the silicon nano/micro structure arrays in the front side and the electrical advantage from the front floating emitter and interdigitated back contact (FFE-IBC) structure in the back surface, both superior optical and electrical properties can be achieved in the solar cell. Through the establishment of the theoretical model for FFE-IBC solar cells with nano/micro structure arrays surface based on the light absorption and carrier transport models, we are able to gain a better insight into the effect of the distribution and aspect ratio of the nano/micro structure arrays, doping concentration and junction depth, interface state density, defects, etc. on the optical absorption and charge transport characteristics. We propose to design and fabricate the high-efficiency (>24%) FFE-IBC solar cells with nano/micro structure arrays surface and solve the scientific & technological issues of the optimal optical trap, the low surface and Auger recombination, the great carrier pump effect and the metallization. The present project will benefit for the future application of silicon based FFE-IBC solar cells with nano/micro structure arrays surface and make contribution to the development of photovoltaic science & technology.

新概念高效太阳电池物理性质与器件应用的探索研究是当代凝聚态物理学科前沿。本项目提出硅基纳微米结构背接触太阳电池物理与器件的创新应用基础研究，主要借助于前表面无电极遮挡的纳微米复合阵列在光学方面和带有前漂浮结的交指式背接触结构 (FFE-IBC) 在电学方面的互补优势，同时实现优越的光、电特性。通过在光吸收模型和载流子输运模型基础上建立硅基纳微米结构阵列FFE-IBC太阳电池光电理论模型，透彻了解纳米结构阵列密度及高宽比、各层掺杂和结深、界面态密度、缺陷等对光吸收及载流子输运的影响；通过理论与实验相结合的方法，设计、制备出高效（>24%）硅基纳微米结构阵列表面FFE-IBC太阳电池原型器件，解决其中最优光陷阱效应、最低表面和俄歇复合、最佳载流子泵浦效应及金属化接触等核心科学和技术问题；为新概念硅基FFE-IBC太阳电池的未来应用作贮备，推动半导体光伏科学与技术的发展。

本面上项目主要利用前表面纳微米复合阵列在光学方面和带有前漂浮结的交指式背接触结构（FFE-IBC）在电学方面的互补优势，进行新型硅纳微米结构背接触太阳电池物理与器件创新基础研究。建立了硅基纳微米结构FFE-IBC太阳电池光电性能理论模型，透彻了解了纳米结构阵列密度及高宽比、各层掺杂和结深、界面态密度、缺陷等对光吸收及载流子输运的影响。结合纳微米结构阵列减反性能、场效应钝化与界面复合损失等因素，开展了优化纳微米结构表面阵列在高效硅基太阳电池上的应用研究。成功设计出转换效率25.1%和制备出第三方认证转换效率22.2%的纳微米结构背接触晶硅太阳电池，解决其中最优光陷阱效应、最低表面和俄歇复合、最佳载流子泵浦效应及金属化接触等核心科学技术问题。