钙钛矿太阳电池致密层和吸收层的制备与光伏性能关系的研究

The novel inorganic-organic hybrid heterojunction perovskite solar cells are mainly composed of the transparent conductive oxide glass, compact layer, perovskite absorber layer, hole-transporting materials and a metal back electrode, and the photoelectric conversion efficiency of 15.6% has been achieved. In this project, the preparation of TiO2 compact layers by hydrolysis-pyrolysis procedure using the metastable TiCl4 solution of deionized water and isopropanol, the preparation of PbX2 and CH3NH3PbX3 thin films containing the TiO2 and ZrO2 scaffold using a low-temperature spin-coating method by dispersing the TiO2 and ZrO2 nanoparticles with different particle size in the solution of PbX2 or the mixed solution of PbX2 and CH3NH3X3, and the preparation of perovskite absorber layers by treating the vapor deposited PbX2 and CH3NH3PbX3 thin films in the CH3NH3X atmosphere are investigated, respectively. The relationship among the preparation, composition, microstructure and properties of the thin films and the photovoltaic performance of the perovskite solar cells is displayed. The interfacial characteristics, energy band gap match-up, heterojunction transition, the carrier transportation and effective collection in the perovskite solar cells are elaborated, and the corresponding energy band gap structural model and the theory of transportation are established, which provide important theoretical basis and technical support to develop the low-cost and scale manufactural perovskite solar cells.

钙钛矿太阳电池是一种新型无机-有机杂化异质结太阳电池，主要由透明导电玻璃、致密层、钙钛矿吸收层、有机空穴传输层、金属背电极五部分组成，目前的光电转换效率已达15.6%。本项目重点利用介稳态的TiCl4醇水溶液等、通过水解-热解法制备TiO2等致密层；研究将不同粒径的TiO2或ZrO2纳米粒子分散到PbX2或PbX2与CH3NH3X的混合溶液、旋涂低温制备含TiO2或ZrO2骨架层的PbX2或钙钛矿薄膜，以及采用PbX2或CH3NH3PbX3作为蒸发源气相沉积相应薄膜，并用CH3NH3X气相处理进一步转化为钙钛矿吸收层；明确相应薄膜的制备、组成、微结构、性质与钙钛矿太阳电池光伏性能之间的关系，阐明其中异质结的界面特性、能隙匹配、异质结过渡、载流子的产生、输运和有效收集问题，建立相应的异质结能带结构模型和输运理论，为发展低成本、可规模化开发利用的钙钛矿太阳电池，提供重要的理论依据与技术支撑。

钙钛矿太阳电池是一种新型无机-有机杂化异质结太阳电池，通常由透明导电玻璃、致密层、钙钛矿吸收层、有机空穴传输层、金属背电极五部分组成，目前的光电转换效率已达23.7%。通过本项目的研究，掌握了TiO2、WO3、ZnO致密层和相应纳米阵列的制备与微结构调控技术，获得了钙钛矿吸收层的气相辅助溶液法、二步溶液法、二步气相法等制备过程的组分调节原理和关键技术参数，明确了钙钛矿太阳电池致密层和吸收层的制备、组成、微结构、性质与光伏性能之间的关系，阐明了其中异质结的界面特性、能级匹配、异质结过渡、载流子的产生、输运和有效收集问题。在空气相对湿度为50~54%条件下，对于未掺杂TiO2致密层，基于厚度596 nm CH3NH3PbI3-xBrx薄膜的平板钙钛矿太阳电池的光电转换效率PCE为14.88%、Voc 1.03 V、Jsc 20.62 mA•cm-2、FF 0.70；对于铌掺杂TiO2致密层，相应平板钙钛矿太阳电池的PCE为15.97%、Voc 0.99 V、Jsc 22.62 mA•cm-2、FF 0.71，TiO2纳米棒阵列的钙钛矿太阳电池的PCE为18.88%、Voc 1.03 V、Jsc 23.95 mA•cm-2、FF 0.77；对于钇掺杂TiO2致密层，相应钇掺杂TiO2纳米棒阵列的钙钛矿太阳电池的PCE为18.32%、Voc 1.04 V、Jsc 23.55 mA•cm-2、FF 0.75；相关理论成果已公开发表研究论文29篇，其中SCI 24篇、EI 3篇，达到了预期研究目标，为发展低成本、可规模化开发利用的钙钛矿太阳电池，提供了重要的理论依据与技术支撑。