Delta掺杂II型InAs/GaAsSb量子点材料及高效中间能带太阳能电池研究

量子点中间能带太阳能电池是一种基于纳米技术和能带工程的新型高效电池，理论效率高达63.1%，是高效利用太阳能的新途径和可行方案，也是当前国际学术界的研究热点。受限于现有周期性叠层量子点材料的制备技术，量子点材料存在载流子寿命较短、光电转换效率较低等问题，性能无法满足高效太阳能电池的要求，成为制约器件性能的最重要因素。本项目基于先进的分子束外延技术，设计并采用Delta掺杂，解决II型InAs/GaAsSb量子点中间能带中电子浓度低的问题，同时修饰量子点能级结构，发展出长寿命、高转化效率的高质量中间能带太阳能电池核心材料。进一步，通过解决II型叠层InAs/GaAsSb量子点材料的可控生长及Delta掺杂II型InAs/GaAsSb量子点材料对器件载流子动力学过程的作用机理等关键科学问题，结合器件结构与工艺的优化，研制出高效中间能带太阳能电池，性能超过目前国际最好水平。

Intermediate-band solar cell (IBSC) is a novel high-efficiency device, with a theoretical efficiency of as high as 63.1%. The core of realizing high-efficiency IBSCs is the design and preparation of high-performance multi-layer quantum dot (QD) materials. Based on the advanced molecular beam epitaxy (MBE) technology, the project emphasizes on studying the Delta-doping InAs/GaAsSb QDs growth and relevant mechanism. By Delta-doping, the type-II InAs/GaAsSb IB with long carriers’ lifetime and high electron concentration will be realized, and the QD energy level structure will be modified to enhance the electron-hole interaction. Meanwhile, the design and fabrication of the IBSC based on the Delta-doping InAs/GaAsSb QD material will be investigated, revealing the effect mechanisms of the Delta-doping InAs/GaAsSb QD IB on the dynamics processes related to carrier generation, transport and collection, exploring new mechanisms for high-efficiency solar cells. By executing the project, the high-efficiency IBSC will be developed, and the theoretical basis and key technologies for developing the high-efficiency solar cells will be offered.