摘 要

Abstract 2

1 绪论 4

1.1概述 4

1.2 钙钛矿发光器件简介 5

1.2.1钙钛矿结构概述 5

1.2.2钙钛矿发光器件的发光原理 6

1.2.3钙钛矿发光器件的发展历史 6

1.3钙钛矿薄膜制备方法 8

1.4钙钛矿发光二极管器件结构 11

1.5 本论文主要研究内容 12

2 钙钛矿薄膜表面形貌的调控以及发光器件的制备 13

2.1实验部分 13

2.1.1钙钛矿薄膜的制备过程 13

2.1.2实验药品及仪器 14

2.1.3实验操作步骤 15

2.2钙钛矿薄膜表面形貌的表征 15

2.2.1钙钛矿薄膜表面形貌的测定 15

2.2.2小结与归纳 16

2.3钙钛矿发光器件性能表征 17

2.3.1钙钛矿发光器件的性能测试 17

2.3.2小结与归纳 19

3总结与展望 20

参考文献 21

致 谢 23

摘 要

有机-无机混合钙钛矿是一种应用潜力非常广阔的材料，对这些化合物的研究自上世纪初就已经开始，但当时主要关注的是该化合物的结构和磁性能。使这类材料的理解和应用向前迈进一步的工作是其电致发光的演示，以及与此同时，导电和半导体杂化钙钛矿的发现。钙钛矿薄膜具有优秀的电光和光电性能（其能量转化效率可以高达20%），应用也十分广泛，例如光伏器件，光电探测器和发光二极管，因此也成为这几年国内外科学们研究的热门材料。其中，无定形CH₃NH₃PbBr₃纳米颗粒的高效绿光发射二极管也成为钙钛矿发光器件的研究重点，作为发射层，CH₃NH₃PbBr₃ 在空气中具有较好的稳定性和较高的激子束缚能级，并且在室温下的开启电压也比较低。最重要的是CH₃NH₃PbBr₃因为其优越而简单的溶液成膜性而备受关注。

本论文通过在钙钛矿（CH₃NH₃PbBr₃）前体溶液中加入适当的添加剂NaBr，通过一步将此溶液旋涂成发光二极管的活性层薄膜。发现了在加入NaBr后可以有效的改善钙钛矿薄膜的表面形貌，从而进一步提升器件的发光性能，钙钛矿发光器件的发光强度最大可以达到4613cd/m²，在提高钙钛矿发光器件的发光强度的同时也提高了器件的效率,器件的外量子效率也达到了0.11%。从而证明了通过加入添加剂改善钙钛矿形貌来改善发光器件的性能是一种十分有意义和有效的方法，相比其它方法，其不仅大大简化了器件的制备工艺，同时也降低了器件制作成本。

关键词：钙钛矿薄膜；发光材料；表面形貌；添加剂；发光二极管

Abstract

Organic-inorganic hybrid perovskites are promising material for its application. The study of these compounds has already begun since the beginning of the last century, but the main concern at that time was the structure and magnetic properties of the compounds. Ishihara et al. Pioneered the study of the optical properties of mixed perovskites, and they explored the exciton properties of layered perovskites. The advancement of the understanding and application of such materials is a demonstration of electroluminescence, as well as the simultaneous discovery of conductive and semiconductive hybrid perovskites. Perovskite thin films have excellent electrooptical and photoelectric properties (the energy conversion efficiency can be as high as 20%), the application is also very wide, such as photovoltaic devices, photodetectors and light-emitting diodes, so it has become popular materials studied by domestic and foreign scientists in the past few years. Perovskite has a variety of different properties because it has independent organic and inorganic components. The inorganic components have good optical and electronic properties as well as excellent mechanical and thermal stability. The organic moiety can adjust these properties and increase the possibility of perovskite deposition on simple substrates on any type of substrate at low temperatures. Recently, perovskite light-emitting diodes (PeLEDs) have begun to attract attention from their distinctive features such as high photoluminescence quantum yield, narrow photoluminescence spectroscopy, long carrier dispersion length, low temperature solution processing technology, etc., while the perovskite can be adjusted by the type and proportion of their own halogen to achieve full visible light emission. However, compared with organic light-emitting diodes (OLEDs) and quantum dots (QLEDs), current efficiency of perovskite light-emitting diodes isn’t very high at room temperature, which limiting its application, but a lot of means can make up for its shortcomings. Among them, the high efficiency green light-emitting diodes of amorphous CH₃NH₃PbBr₃ nanoparticles have become popular research for perovskite light-emitting devices. As the emission layer, CH₃NH₃PbBr₃ has good stability and high exciton binding energy in air, and the opening voltage is relatively low at room temperature. The most important advantage of CH₃NH₃PbBr₃ its superior property of simple solution film-forming makes it draw attention.

In this paper, the perovskite (CH₃NH₃PbBr₃) precursor solution was spin-coated into the active layer film of the light-emitting diode by adding the appropriate additive NaBr . It was found that the surface morphology of the perovskite film could be improved by adding NaBr, and the luminescence performance of the perovskite light-emitting device could be also enhanced. The luminance of the perovskite light-emitting device increased to 4613cd / m²,the efficiency of the device also improves , the external quantum efficiency of the device has reached 0.11%. It is proved that the improvement of the perovskite morphology by adding additives to improve the performance of the light-emitting device is a quite meaningful and effective method. Compared with other methods, it not only greatly simplifies the preparation process of the device, but also reduces the device fabrication cost.