钙钛矿薄膜成分与结晶过程的调控

发布时间：2018-02-09 22:12

本文关键词： 钙钛矿太阳能电池甲胺铅碘甲脒铅碘稳定性大晶粒　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：有机铅碘钙钛矿材料(如CH_3NH_3PbI_3,MAPbI_3和NH_2CH=NH_2PbI_3,FAPbI_3)具有合适的带隙、低廉的成本,且可溶液法制备等优势,引起了人们的广泛关注。被认为是目前最有商业化前景的新一代太阳能电池器件之一。2009年,有机无机杂化钙钛矿的光电转换效率只有3.8%,经过短短几年的发展,其认证的效率已经达到22.1%,基本满足商业化应用的要求。钙钛矿太阳能电池的稳定性是目前限制其进一步发展的瓶颈问题。本文通过优化钙钛矿材料成分、调控钙钛矿薄膜结晶过程两个方面来提高其稳定性。MAPbI_3材料是研究最为广泛的钙钛矿阳能电池材料,但稳定性相对较差。通过调控钙钛矿的有机组分,如在MAPbI_3中引入FA可以明显提高其稳定性。然而FA组分的引入容易生成非钙钛矿相δ-FAPbI_3,影响器件的性能。本文通过优化固液离子交换温度,有效避免黄相δ-FAPbI_3的生成,原位制备了纯相的FAxMA1-x PbI_3,而且实现了对钙钛矿材料有机组分的连续调控。经过优化的FAxMA1-x PbI_3钙钛矿太阳能电池的率达到了15.5%,无明显滞后。除了钙钛矿材料自身的稳定性外,外界环境中的水分等也是影响其稳定性的重要因素。水分子容易通过薄膜中的晶界进入到钙钛矿薄膜的内部引起薄膜的降解。因此,控制薄膜中晶界的数量是提高钙钛矿材料稳定性的另一重要手段。本文通过引入有机氯化物以形成较为稳定的中间相,中间相在高温逐渐分解而得到钙钛矿薄膜。有机氯化物的引入明显延长钙钛矿薄膜结晶时间,最终使几十纳米的小晶粒经过奥斯瓦尔德熟化生长成几微米的大晶粒。晶界的数量的减少一方面降低了载流子内部复合,提高了光电效率,到达17%;另一方面,钙钛矿电池器件的稳定性也得到了明显改善,空气中放置400 h后依然能保持90%的初始效率,而相对比的小晶粒钙钛矿太阳能电池放置350 h时就已经不能正常工作。通过本文的研究,深入分析了钙钛矿材料成分、结晶性与器件的效率和稳定性之间的内在关系,这为进一步提高钙钛矿太阳能电池器件的稳定性提供了必要的实验基础和理论支持。
[Abstract]:Organic lead-iodide perovskite materials (such as CHC _ 3NH _ 3PbI _ + _ 3P _ bI _ 3 and NH _ 2CHI _ (NH _ 2PbI _ 3) / FAPbI _ 3) have the advantages of suitable bandgap, low cost, and can be prepared by solution method. In 2009, the optoelectronic conversion efficiency of organic-inorganic hybrid perovskite was only 3.8%. The efficiency of its certification has reached 22. 1, which basically meets the requirements of commercial applications. The stability of perovskite solar cells is the bottleneck that restricts its further development. In this paper, the composition of perovskite materials is optimized. Controlling the crystallization process of perovskite thin film to improve its stability. MAPbI _ 3 is the most widely studied material for perovskite positive battery, but its stability is relatively poor. For example, introducing FA into MAPbI_3 can obviously improve its stability. However, the introduction of FA component can easily produce non-perovskite 未 -FAPbI3, which affects the performance of the device. In this paper, the formation of 未 -FAPbI3 in yellow phase is effectively avoided by optimizing the solid-liquid ion exchange temperature. The pure phase FAxMA1-x PbI _ 3 was prepared in situ, and the continuous control of the composition of perovskite material was realized. The optimized FAxMA1-x PbI_3 perovskite solar cell rate reached 15.5g, and there was no obvious lag. In addition to the stability of perovskite material itself, Water in the outside environment is also an important factor affecting the stability of the perovskite film. Water molecules can easily enter the perovskite film through the grain boundary of the film and cause the degradation of the perovskite film. Controlling the number of grain boundaries in the films is another important means to improve the stability of perovskite materials. In this paper, organic chlorides are introduced to form stable mesophase. Perovskite films were obtained by decomposition of mesophase at high temperature. The introduction of organic chlorides significantly prolonged the crystallization time of perovskite films. Finally, dozens of nanocrystalline grains grow into several microns of large grains after Oswald's ripening. On the one hand, the reduction in the number of grain boundaries reduces the internal recombination of carriers, improving the photoelectric efficiency to 17; on the other hand, The stability of perovskite battery devices has also been improved obviously, and the initial efficiency of 90% can be maintained after being placed in air for 400h. However, the contrast small grain perovskite solar cell can not work normally when it is placed for 350 h. The relationship between the composition, crystallinity and the efficiency and stability of the perovskite material is deeply analyzed through the research in this paper. This provides necessary experimental and theoretical support for further improving the stability of perovskite solar cell devices.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;TM914.4

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