钙钛矿太阳能电池中钙钛矿层及电子传输材料的制备研究

Investigation on Preparation of Perovskite Layer and Electron-Transport Materials for Perovskite Solar Cells

摘要: 在有机无机杂化的卤素钙钛矿电池中，电子传输材料及其与吸收层之间的界面对提高光电转化效率起着重要作用。电子传输层的介观结构直接影响钙钛矿层的生长情况，而钙钛矿层的微结构决定了电池的稳定性和寿命。本文采用水热法制备TiO₂纳米棒阵列薄膜作为电子传输材料，通过磁控溅射法在阵列薄膜与FTO衬底间插入致密TiO₂阻挡层。研究结果发现TiO₂阻挡层能够有效抑制电子空穴对在界面的复合，从而提高了开路电压。采用一步和两步化学溶液法制备了CH₃NH₃PbI₃钙钛矿层，发现两步法制备的CH₃NH₃PbI₃晶体质量明显提高，有效增加了电池的短路电流，其光电转换效率比一步法提高了一倍。

Abstract: In organic-inorganic hybrid halogen perovskite solar cell, the electron transport material and its interface with absorption layer play an important role in the efficiency of photoelectrical conversion. The mesoscopic structures of the electron-transport layer will directly influence the growth of perovskite layer, whose microstructures are crucial for the stability and life-span of solar cells. In this work, the layer of TiO₂ nanorod arrays grown by hydrothermal method was used as the electron transport material, and a compact TiO₂ thin film deposited on FTO substrate by magnetron sputtering as the blocking layer. It is found that the compact TiO₂ layer can effectively inhibit the recombination of electron-hole pairs at interface and thus open-circuit voltage is raised. The perovskite layers were prepared via one-step or two-step chemical solution deposition. The quality of the two-step prepared perovskite layer is much better than the one-step one; the corresponding short-circuit current and efficiency are greatly enhanced compared with the former.