CuInGaSe2太阳能电池界面结构、界面态及其钝化

界面态的出现总是不利于CuInGaSe2薄膜太阳能电池的综合性能，它减小开路电压并降低光电转换效率。为最大限度削弱界面态的不利影响,拟用第一性原理计算、原子模拟和器件模拟三种研究方法，在电子、原子和器件三种结构层次上系统研究Mo背电极|CuInGaSe2吸光层|CdS缓冲层|ZnO窗口层形成的界面的局域晶格结构（晶向匹配、晶格失配、紧邻层成分和晶格缺陷等）和电学性质（能带结构、电子能态密度、电荷密度和成键态等）。探讨界面态出现的微观机制和钝化方法，研究其出现的位置、数量对电池性能（开路电压、短路电流、光电转换效率和填充因子）的影响规律。使用三种方法可加快研究进程。目的是用三种结构层次的定量数据理解电池界面局域结构-界面态-电池性能互动关系，揭示界面态对电池光电性能变化的微观机理，为设计电池界面成分、尽力减缓界面态的不利影响、确定薄膜制备工艺参数提供参考，为提高电池性能提供理论引导和帮助。

Interface states in CuInGaSe2 thin-film solar cell always do harm to its overall performance by reducing both open-circuit voltage and photoelectric conversion efficiency. In order to maximally weaken the negative impacts of interface states, we will use the first-principles calculation, atomistic simulation and device simulation to systematically study the local structures and electronic properties of the interfaces located in Mo-back electrode | CuInGaSe2 light-absorbing layer | CdS buffer layer | ZnO window layer, at electronic, atomic and device structural level, respectively. For the local structures, lattice direction match, lattice constant mismatch, chemical composition in the adjacent layer and lattice defects will be considered. For the electrical properties, band structures, electronic density of states, charge density and bonding state will be calculated. We will discuss the microscopic appearance mechanism of interface states and possible passivation methods for them, and we will also investigate their appearance positions in the band gap, magnitude and their influences on cell performances (open-circuit voltage, short-circuit current, photoelectric conversion efficiency and fill factor). Usage of three simulation methods can speed up the research progress. The aim of this research is to understand the relationship among the local structures of the interfaces, interface states, and CuInGaSe2 thin-film solar cell performances, and to to reveal the micro-mechanism of photoelectric changes introduced by interface states. As theoretical guides, quantitative results at three structural levels will be helpful to design chemical components at the interfaces, to best reduce negative effects of interface states, to select preparation parameters of the thin films, and to improve the cell's performances.