基于纳米线陷光的无光刻背接触异质结太阳电池研究

It is one of the important research topics to develop more efficient and low-cost crystalline silicon solar cells. . Back-contact+heterojunction is widely accepted as a technical scheme for high efficiency crystalline silicon solar cell. In this project, the hot filament CVD combined with metal mask technology is used for photolithography-free graphical amorphous silicon film growth and achieving effective separation of the back junction and the back field. By optimizing process parameters, the preparation process for the back junction and the back field is simplified to only six steps. The low-cost nanowire array instead of the conventional Pyramid is used as the light trapping structure. By sufficiently passivating nanowires, it is expected to obtain high short-circuit current. The light trapping structure and cell structure are optimized by simulation calculation. The transport mechanism of the device will be revealed by theoretical and experimental study.. Based on the successful completion of this project, a set of perfect solution for preparation of photolithograpy-free back contact solar cell will be given, which provides the experimental and theoretical basis for the preparation of high-efficiency and low-cost back contact solar cell.

研究发展更加高效和低成本的晶硅太阳电池技术，是当前光伏领域最为重要的研究课题之一。. 针对目前公认的背接触+异质结高效晶硅电池技术方案，本项目通过将热丝化学气相沉积和金属掩模技术结合，充分发挥薄膜生长的影蔽效应和保角沉积特征，进行无光刻下的图形化薄膜生长，通过介质膜绝缘层有效分离背结和背场，优化工艺参数，简化背结和背场制备工艺流程（只需六步）；采用低成本纳米线陷光结构代替常规的金字塔结构，通过充分钝化纳米线表面，有效发挥其陷光作用，来获得高的电池短路电流；通过模拟计算指导纳米陷光结构和电池结构的优化，通过对载流子电输运过程的研究，揭示其输运机制。. 通过本项目的顺利完成，提出一套完善的基于纳米线陷光的无光刻背接触电池制备方案，为制备高效低成本的背接触晶硅电池提供实验和理论依据。

占光伏市场95%以上份额的是晶硅太阳电池，目前最高效的晶硅电池采用的是背接触+异质结（HBC）的电池结构，但由于HBC电池一般要使用光刻技术，因此成本较高，不易产业化。. 本项目主要研究不使用光刻的HBC电池制备方法，其中包括：硅基纳米线限光结构的制备、钝化，免掺杂氧化物半导体材料的大面积、低成本制备工艺，及硅纳米线和免掺杂氧化物载流子选择层在HBC电池上的应用。利用金属辅助刻蚀技术制备出表面反射率低于2%的硅纳米线，利用首创的热丝反应升华法沉积大面积MoOx膜作为硅异质电池的空穴传输层，利用溶液法在制绒硅衬底上生长致密、超薄的TiO2、SnO2、ZnO膜作为电子传输层，并结合金属掩膜技术制备出HBC电池，电池效率达到21%。整个电池制备流程只有5步，大大简化了HBC的制备工艺。. 同时利用纳米线制备径向异质结太阳电池，电池转换效率达到16.02%。利用热丝反应升华法制备MoOx/c-Si异质结电池，电池转换效率达到21.1%。