基于氧化锌纳米棒阵列的杂化钙钛矿太阳能电池研究

Perovskite solar cell is one of the research hotspots of solar photovoltaic technology due to its higher efficiency than Si solar cells. Usually the mesoporous titanium dioxide (TiO2) is used as electron collecting electrode in the hybrid perovskite solar cells, with the process of high temperature annealing. The band structure of Zinc Oxide (ZnO) is similar with TiO2, but the electron mobility of the ZnO is much higher. In addition, ZnO can be prepared by several of low temperature processes. Therefore, ZnO is expected to replace TiO2 as the electron collecting electrode in the hybrid perovskite solar cells with the similar or higher conversion efficiency. At present, the research on hybrid perovskite solar cells using ZnO as electron collecting electrode only started just now and a few reports demonstrate that the conversion efficiency is lower than the device based on TiO2. The results may be associated with the microstructure, crystal quality and other factors. In this project ZnO nanorod arrays sensitized by quantum dots or treated by UV-Ozone are introduced as the electron collecting electrode in the hybrid perovskite solar cells. The stability of the device will be improved and the cost of the device will be reduced by the replacement of Spiro-OMeTAD with p-type compound. And the efficiency of the device will be improved by the research of the microphysical process and physical mechanism.

钙钛矿太阳能电池的预期效率远超出硅基太阳能电池，使其成为目前光伏技术的热点之一。通常有机/无机杂化钙钛矿太阳能电池采用介孔TiO2作为电子收集电极，但是制备过程需要高温退火。ZnO具有类似的能级结构，电子迁移率明显高于TiO2，各种ZnO材料均可采用低温工艺制备。因此，ZnO有望取代TiO2作为电子收集电极，并获得同样甚至更高的光电转化效率。目前基于ZnO的钙钛矿太阳能电池的研究还处于起始阶段，仅有的几个报导的器件效率明显低于TiO2，这可能与ZnO和钙钛矿复合薄膜的微观结构、晶体质量等有关。本项目拟采用ZnO纳米棒阵列作为电子收集电极，对其进行量子点敏化和紫外臭氧的改性处理来改善与钙钛矿层的界面性能，并且研究p型化合物替代传统的Spiro-OMeTAD作为空穴传输层，来提高器件的稳定性和降低器件的成本。并通过研究器件的微观物理过程和物理机制，探索有效提高器件效率的方法与途径。

钙钛矿太阳能电池的预期效率远超出硅基太阳能电池，使其成为目前光伏技术的热点之一，但是由于传统钙钛矿太阳能电池应用的有机Spiro-OMeTAD材料作为空穴传输层，导致电池的成本较高并且稳定性较差，钙钛矿太阳能电池的高成本和低稳定性等问题还有待进一步解决，电子传输层与钙钛矿吸收层之间的界面性质对器件的性能影响及物理机制还不太明了。在本项目支持下，我们主要对相关问题进行了深入研究，获得的主要成果如下：（1）采用简单快速且易于实现大规模生产的电化学沉积法制备ZnO纳米棒，并利用简单的化学浴方法在ZnO纳米棒上生长了不同的量子点来进行改性处理，不同的量子点材料的加入增加了对于光的吸收，并改善了电子传输层与钙钛矿吸收层之间的界面性能。（2）采用一步法和两步法制备了ZnO纳米棒上的钙钛矿薄膜，通过实验条件的调节得到了晶粒均匀、晶型完好、表面光滑并且大晶粒的钙钛矿薄膜，并制备了高性能的纳米ZnO基杂化钙钛矿太阳能电池。（3）采用电化学沉积法合成了氧化亚铜、硫氰酸亚铜和氧化镍三种无机空穴传输层材料并制备了基于这三种材料的钙钛矿太阳能电池，并对于三种空穴传输层制备的钙钛矿太阳能电池进行了性能的对比分析。（4）制备了纳米ZnO基杂化钙钛矿太阳能电池并对影响电池性能的因素进行了分析并提出了电池制备的改进方法。相关研究结果共发表SCI论文7篇，其中影响因子大于3.0的论文7篇，中科院分区一区的3篇。