具有三维径向纳米结构的非晶硅中间带薄膜材料及太阳电池应用的可行性研究

Amorphous Si thin film solar cell material is a key material to solve the energy crisis problem and have important applications in Building Integrated Photovoltaic (BIPV). However, due to the low carrier mobility, weak infrared response and high reflectance loss, the single-junction a-Si solar cell has low efficiency below 10%. The intermediate band (IB) solar cell is a promising third-generation solar cell that could possibly achieve very high efficiency above the Shockley-Queisser limit. The project is subjected to study a novel 3D amorphous Si intermediate band material with radical nanostructure, improving the carrier collecting ability, reducing reflectance loss and improving the infrared response. The research includes 1) the controlled synthesis and doping of ordered ZnO radial nanostructure and its mechanism of light trapping; 2)the effect of interface states and heterostructure barrier on carrier transport and the methods to reduce them; 3) the realization, optimization and control of impurity intermediate band in amorphous Si by multiple target magnetron sputtering with hydrogen, and choosing the proper impurity with the guide of the detailed balanced theory 4) study the carrier transport process and novel photoelectric conversion mechanism in the novel amorphous Si intermediate band material with radical nanostructure

非晶硅薄膜太阳电池材料是解决能源危机问题以及实现光伏建筑一体化的重要材料。然而，长波响应差、反射损耗高以及收集效率低等问题制约了单结非晶硅薄膜电池效率的提高。中间带材料通过双光子接力吸收，可实现可见与红外波段兼容的宽谱响应。本课题拟研究具有三维径向纳米结构的非晶硅中间带材料，以期同时实现宽谱响应、高效陷光及有效的载流子输运。研究内容包括1）氧化锌纳米有序结构可控制备、掺杂控制及非晶硅-氧化锌复合纳米阵列的陷光机理2）纳米结构表面态及界面势垒对载流子输运的影响以及降低途径3）利用氢化磁控共溅射技术，探索在非晶硅中半填充深能级杂质中间带的实现途径及调控方法4）研究具有径向纳米结构的非晶硅杂质中间带材料的载流子输运过程和新型光电转换机制，包括影响载流子发射截面与俘获截面差异的物理机制等，进而探索具有纳米结构的非晶硅中间带材料对提高太阳光谱红外波段光谱响应的可行性。

非晶硅薄膜太阳电池材料是解决能源危机问题以及实现光伏建筑一体化的重要材料。然而，长波响应差、反射损耗高以及收集效率低等问题制约了单结非晶硅薄膜电池效率的提高。本课题探索了具有三维径向纳米结构的非晶硅中间带材料及新型三维径向纳米结构的太阳电池的制备方法及途径，共计发表SCI文章30篇，申请专利6项，软件著作权3项，全面完成了项目立项之初的各项指标。取得的主要成果如下：1）提出了纳米线表面包裹TCO背电极的径向结太阳电池新结构，使质量低的硅纳米线旧结构电池填充因子相对提高13.4%；2）利用水热法在硅基、玻璃及柔性衬底上制备出ZnO纳米棒、纳米花等多种纳米结构；3）利用氢化磁控共溅射技术，研究了氢化a-Si(Ti):H的结构、光学及电学特性，制备出了非晶硅a-Si(H):Ti中间带电池，其红外波段（700nm-900nm）的QE响应有明显增大，而开压的下降则归结于Ti在非晶硅中形成的深能级杂质带直接参与了电输运；4）制备非晶硅纳米径向太阳电池，其平均光反射率下降86.8%，短路电流密度提高22%;5）制备出钙钛矿为吸收层的三维立体微纳结构薄膜电池,其效率达到18.5%。