硫化锑/铋纳米结构太阳电池的表界面结构调控和器件性能研究

Nanostructured solar cells have the potential to realize relatively higher photon-to-electricity conversion efficiency through low-cost fabrication route. Research results indicate that the key physical issues limiting a higher efficiency are the trapping, recombination, and back-tunneling of charge carriers when tranversing the nanoscale interfaces.The above processes are critically dependent on the defect structures and energy band matching in the interface. The surface/interface structures of nanostructured solar cells and materials are rather complex, and it lacks physical principles and management approach to nanoscale surface/interface structure manipulation.In this project, we will focus on nanostructured solar cells of antimony sulfide and bismuth sulfide that have large optical absorption coefficients and are of abundance on the earth and environment friendly, systematically investigate the physical mechanisms and methods for nanoscale surface/interface defect structure and defect passivation, analyze the impact of surface/interface defects on the transport of charge carriers,study the influence of conduction and valence band misfit in the hetero-interface on the transport and tunneling of charge carriers, and figure out the effect of electric dipole on the energy band structure and directed transport of charge carriers,so as to obtain antimony sulfide and bismuth sulfide nanostructure photovoltaic devices with higher short-circuit current, open-circuit voltage, and fill factor. The successful implementation of this project will lay a solid ground for improving the photon-to-electricity conversion efficiency, and have significant implications for enriching the overall applications of solar electricity.

纳米结构太阳电池有望通过低成本制造实现较高光电转换效率。研究表明，影响纳米结构太阳电池光电转换效率的关键物理因素是载流子跨越纳米尺度界面过程中的束缚、复合以及反向隧穿问题。而以上过程严格受界面的缺陷结构和能带结构匹配程度所约束。纳米结构太阳电池及材料表界面结构非常复杂，缺乏纳米尺度表界面结构调控的物理原理和调控方法。本项目拟以硫化锑和硫化铋（重要的光伏材料：光吸收系数大、储量丰富、环境友好）纳米结构太阳电池为主要研究对象，系统研究纳米尺度表界面缺陷结构及缺陷钝化的物理机制和方法，分析表界面缺陷对载流子输运的影响，探索异质界面能级失配度对载流子输运及隧穿的影响规律，认识界面电偶极对能带结构及载流子定向输运作用，以获得具有较高开路电压、短路电流、填充因子的硫化锑、硫化铋纳米结构光伏器件。该项目的成功实施将为提高纳米结构太阳电池光电转换效率奠坚实基础，对丰富太阳能发电的综合利用具有深远意义。

发展了硫化物薄膜太阳电池的制备方法，澄清了界面缺陷对载流子复合动力学的影响规律，提出了改进薄膜太阳电池性能的界面修饰方法，获得了性能稳定的全无机薄膜太阳电池器件；所获得的柔性太阳电池效率为同时期最高水平，论文成果被选为杂志封面；所研制的柔性电极材料性能优异，已经进入中试生产阶段，经济效益和社会效益前景可观。. 项目执行期间，共发表SCI收录论文12篇，其中包括封面论文1篇，特邀综述论文1篇，其中2篇论文获得第八届安徽省自然科学优秀学术论文三等奖；申请国家发明专利6项，授权国家发明专利5项。. 项目负责人入选国家百千万人才工程，课题骨干1人晋升为副研究员，1名博士后被评为优秀博士后，2名研究生获得国家奖学金。