基于两步旋涂法的高性能钙钛矿太阳能电池研究

发布时间：2018-06-25 16:09

本文选题：钙钛矿太阳能电池 + 两步旋涂法　；参考：《中国矿业大学》2017年硕士论文

【摘要】：自从有机-无机杂化钙钛矿型铅卤化合物问世以来,钙钛矿太阳能电池(PSCs)成为光伏科技领域的一个重点研究课题,因为钙钛矿材料具有载流子迁移率高、电子激发能低以及载流子传输距离长等诸多优点。在钙钛矿太阳能电池的结构中,钙钛矿层作为器件的核心部件承担着光吸收并产生电子和空穴的作用。因此,制备高质量的钙钛矿薄膜是提升器件光电性能的关键。高质量的钙钛矿薄膜应具有覆盖率高、致密连续以及均匀平坦的特点,这样才可以提高吸光度,抑制电荷复合,提升钙钛矿太阳能电池的光电转换效率。本文通过优化钙钛矿薄膜的制备工艺,控制钙钛矿晶粒的结晶与生长以及调整钙钛矿材料的能带结构,从而改善了钙钛矿薄膜的表面形貌及结晶性并提升了钙钛矿太阳能电池的光电性能。主要的研究内容及结果如下:1.作者将预旋涂CH3NH3I异丙醇溶液的工艺应用于两步旋涂法中制备钙钛矿薄膜。XRD、SEM以及UV-Vis等测试手段表明,预旋涂15 mg/m L的CH3NH3I的异丙醇溶液的制备工艺能够获得高质量的CH3NH3PbI3薄膜。在此基础上制备介孔结构的钙钛矿太阳能电池,该工艺将电池的光电转换效率由原始的9.24%提升至12.4%。2.作者将高沸点溶剂引入到CH3NH3I异丙醇溶液中,研究发现添加正丁醇溶剂可以有效地提升钙钛矿太阳能电池的光电性能,其原因在于掺入适量的正丁醇溶剂可以增强CH3NH3PbI3晶粒的结晶性,改善钙钛矿薄膜的表面形貌并促进钙钛矿薄膜对光的吸收。在掺入2%正丁醇的条件下获得了光电转换效率高达14.64%的钙钛矿太阳能电池。3.为了改善钙钛矿薄膜的表面形貌并促进钙钛矿薄膜对光的吸收,作者将甲脒离子(HC(NH2)2+,FA+)引入到CH3NH3PbI3(MAPbI3)的晶体结构中,制备出混合有机阳离子的(MA)1-x(FA)xPb I3(x=0-1)钙钛矿型薄膜。研究发现FA+可以改变钙钛矿的晶格参数,降低钙钛矿的能带隙,因而可以吸收更多的可见光及近红外光。此外,将(MA)0.875(FA)0.125PbI3钙钛矿薄膜应用于介孔结构的钙钛矿太阳能电池中获得了高达18.63 mA/cm2的短路电流密度以及13.44%的光电转换效率。本研究成功制备出多种高质量的钙钛矿薄膜,为组装高性能的钙钛矿太阳能电池在钙钛矿薄膜的工艺制备、形貌改善及新材料探索方面提供了新思路。
[Abstract]:Since the advent of organic-inorganic hybrid perovskite-type lead halides, perovskite solar cells (PSCs) have become an important research topic in the field of photovoltaic science and technology, because perovskite materials have high carrier mobility. The electron excitation energy is low and the carrier transport distance is long. In the structure of perovskite solar cells, perovskite layer acts as the core component of the device to absorb light and produce electrons and holes. Therefore, the preparation of high-quality perovskite films is the key to improve the optoelectronic properties of the devices. The high quality perovskite film should have the characteristics of high coverage, compact continuity and even flatness, so as to increase the absorbance, suppress the charge recombination and improve the photoelectric conversion efficiency of the perovskite solar cell. By optimizing the preparation process of perovskite films, the crystallization and growth of perovskite grains and the adjustment of the energy band structure of perovskite materials are controlled. Thus, the surface morphology and crystallinity of perovskite thin films are improved, and the optoelectronic properties of perovskite solar cells are improved. The main contents and results are as follows: 1. The prespin coating process of Ch _ 3NH _ 3i isopropanol solution has been applied to the preparation of perovskite thin films by two-step spin-coating method. The results of UV-Vis show that the preparation of Ch _ 3NH _ 3i isopropanol solution with prespin coating of 15 mg/m L can obtain high quality Ch _ 3NH _ 3PbI _ 3 thin films. On this basis, mesoporous perovskite solar cells were prepared. The photovoltaic conversion efficiency of the cells was increased from 9.24% to 12.44.2%. The high boiling point solvent was introduced into Ch _ 3NH _ 3i isopropanol solution. It was found that adding n-butanol solvent could effectively improve the photoelectric performance of perovskite solar cells. The reason is that adding proper amount of n-butanol solvent can enhance the crystallinity of Ch _ 3NH _ 3PbI _ 3, improve the surface morphology of perovskite film and promote the absorption of light of perovskite film. The photovoltaic conversion efficiency of perovskite solar cells with 2% n-butanol was obtained as high as 14.64%. In order to improve the surface morphology of perovskite thin films and promote the photoabsorption of perovskite films, the (MA) 1-x (FA) xPb I3 (x0-1) perovskite films with mixed organic cations were prepared by introducing formamidine ion (HC (NH2) 2 + FA) into the crystal structure of CH3NH3PbI3 (MAPbI3). It is found that FA can change the lattice parameters of perovskite and reduce the band gap of perovskite so that it can absorb more visible and near-infrared light. In addition, the (MA) 0.875 (FA) 0.125PbI3 perovskite thin film was used in mesoporous perovskite solar cells to obtain short circuit current density of 18.63 mA/cm2 and photoelectric conversion efficiency of 13.44%. In this paper, a variety of high quality perovskite thin films have been successfully prepared, which provides a new idea for the preparation of perovskite thin films, the improvement of morphology and the exploration of new materials for assembling high performance perovskite solar cells.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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