氢卤酸及氨水添加剂对钙钛矿薄膜形貌影响及电荷转移的研究

发布时间：2018-03-07 10:14

  本文选题：钙钛矿形貌　切入点：添加剂　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：钙钛矿太阳电池作为新兴的薄膜太阳电池,由于其优异的光电性能:高的载流子迁移率、合适的带隙、高的摩尔消光系数,在近年来有了喜人的研究成果。作为钙钛矿太阳电池结构中的重要的吸收光的部分,钙钛矿薄膜的质量对钙钛矿太阳电池的性能有举足轻重的影响,制备高质量的钙钛矿薄膜是科学工作者的研究热点之一。为了制备高质量的钙钛矿薄膜,选取了向前驱体溶液中加入添加剂的方法。首先选取了氢卤酸作为添加剂,以一定的体积比加入到前驱体溶液中,制备的钙钛矿薄膜形貌、结晶性都有较大的提高,将钙钛矿太阳电池的光电转换效率从9.66%提高到15.2%。利用反溶剂法结合XRD和红外分析,发现了一种全新的中间相产物:MAI-PbI2-DMF-xHX(X=Cl、Br、I)。从晶体的形核理论出发,结合中间相的形成,对氢卤酸的作用机制给出了合理的解释。在氢卤酸作为添加剂取得成功之后,选取了碱性的氨水作为添加剂制备了钙钛矿薄膜,形貌和结晶性有一定的提高,电池的光电转换效率提高到了 13.5%。钙钛矿太阳电池的效率的提高离不开对其机理的深入理解,只有对电池内部的电荷传输的机理有深刻的理解,才能从优化电池的结构和材料上提高钙钛矿太阳电池的光电转换效率。利用瞬态吸收技术,研究了钙钛矿薄膜的质量对自身及器件内电荷复合的影响,高质量的钙钛矿薄膜中的载流子复合多以电子-空穴的直接复合为主,而在器件中高质量的钙钛矿薄膜能抑制TiO2的导带电子和Spiro上的价带空穴之间的复合。研究了 TiO2和钙钛矿及钙钛矿和Spiro之间的电荷复合问题,得到的时间尺度在100～300 ns,与文献结果基本一致。这部分的研究为钙钛矿薄膜的质量评价提供了一个新的思路,也对钙钛矿电池内部的电荷转移的理解有很大的帮助。
[Abstract]:As a new thin film solar cell, perovskite solar cell has excellent photoelectric properties: high carrier mobility, suitable band gap, high molar extinction coefficient, As an important part of the structure of perovskite solar cells, the quality of perovskite films plays an important role in the performance of perovskite solar cells. The preparation of high quality perovskite thin films is one of the hot research topics of scientists. In order to prepare high quality perovskite films, the method of adding additives to the precursor solution is selected. The morphology and crystallinity of the perovskite films prepared by adding a certain volume ratio to the precursor solution have been greatly improved. The photoelectric conversion efficiency of the perovskite solar cells has been increased from 9.66% to 15.2.The antisolvent method combined with XRD and infrared analysis was used. A new kind of mesophase product:: MAI-PbI2-DMF-xHXHXOXXHXHXHXHXHXHXHXHXHXHXHXHXHXHXHXHXHXHXHXHX, a new kind of mesophase product, was found. Based on the nucleation theory of crystal and the formation of mesophase, the mechanism of action of hydrohalogenic acid was explained reasonably. Perovskite thin films were prepared with alkaline ammonia as additive. The morphology and crystallinity of perovskite thin films were improved, and the photoelectric conversion efficiency of the battery was raised to 13.5.The efficiency of perovskite solar cells could not be improved without a thorough understanding of its mechanism. Only when we have a deep understanding of the mechanism of charge transfer inside the cell can we improve the photoelectric conversion efficiency of the perovskite solar cell by optimizing the structure and materials of the battery. The effect of the quality of perovskite film on the charge recombination of the perovskite film and the device is studied. The carrier recombination in the high quality perovskite film is mainly composed of electron-hole direct recombination. The high quality perovskite film in the device can inhibit the recombination between the conduction band electron of TiO2 and the valence band hole in Spiro. The problem of charge recombination between TiO2 and perovskite and between perovskite and Spiro is studied. The obtained time scale is 100 ~ 300ns, which is basically consistent with the results of the literature. This part of the study provides a new idea for the quality evaluation of perovskite thin films, and it is also helpful to understand the charge transfer inside perovskite cells.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;TM914.42
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本文编号：1579023