【作者】 王宏；

【导师】 徐庆宇；

【作者基本信息】 东南大学 ， 凝聚态物理， 2020， 硕士

【摘要】 步入21世纪,人类社会的快速发展,对资源的需求也日趋增加,开发新型清洁能源至关重要。有机无机杂化卤化物钙钛矿材料因其具有适宜的带宽、光吸收能力强、高载流子迁移率等优异的光电特性,成为清洁能源开发的重要材料。目前在太阳能电池领域有机无机杂化钙钛矿材料已经引起了人们的广泛关注,其制备的钙钛矿太阳能电池光电转换效率高,具有巨大的应用前景,可以推动人类社会的可持续发展。然而,钙钛矿薄膜的质量对太阳能电池器件性能和寿命起着关键的作用。在各种光学薄膜沉积技术中,脉冲激光沉积技术（Pulsed Laser Deposition,PLD）具有易操作且所制备的薄膜致密均匀高质量等优点。因此,本文将脉冲激光沉积技术引入到无机钙钛矿薄膜的制备,并应用到太阳能电池当中,主要完成以下二个方面的研究工作:1、利用脉冲激光沉积技术取代旋涂法制备CsPbBr₃薄膜并应用到钙钛矿太阳能电池当中。通过溶液法合成CsPbBr₃单晶粉末并被压制成靶材。利用脉冲激光沉积技术轰击CsPbBr₃靶材,所形成的CsPbBr₃薄膜展示出优异的荧光性能,在高湿度环境下能保持良好的稳定性。同时在制备太阳能电池的过程中,我们观察到形成的CsPbBr₃等离子体可以渗透到介孔Ti O₂层里,并能够均匀分布其中。由此分别研究了介孔Ti O₂和CsPbBr₃薄膜的厚度对器件性能产生的影响。将厚度不断优化得到最佳性能的CsPbBr₃钙钛矿太阳能电池PCE达到6.3%,开路电压为1.37 V,填充因子占比72%,短路电流密度是6.4 m A/cm²。2、采用二步法制备了CsPbBr_xI_3-x（x=0,1,2,3）薄膜。以Cs Br、Cs I、PbBr₂、PbI₂为基本原材料制备成四种靶材,根据所要形成的薄膜将相应的二个靶材放入腔体,按着对应的顺序沉积,通过调节衬底温度,沉积的薄膜通过热扩散进行化学反应可以在衬底上形成CsPbBr_xI_3-x（x=0,1,2,3）薄膜。通过脉冲激光沉积技术二步法制备的CsPbBr_xI_3-x（x=0,1,2,3）薄膜可以精确的控制厚度,并具有优异的荧光性能。我们对于所制备的CsPbBr_xI_3-x（x=0,1,2,3）薄膜荧光性能进行了测试,观察到CsPbBr_xI_3-x（x=0,1,2,3）薄膜半峰宽度范围在18.9-40.8 nm,荧光光谱峰值位置可以在513 nm到663 nm之间调节。通过测量的时间分辨荧光光谱拟合出CsPbBr_xI_3-x（x=0,1,2,3）薄膜的衰减时间分别是8.93 ns,15.59 ns,7.49 ns,14.07 ns。通过脉冲激光沉积技术制备的高质量CsPbBr_xI_3-x（x=0,1,2,3）薄膜成本低廉操作简单,展示出优异的光电性能,可应用于无机钙钛矿太阳能电池、光电子器件等领域。更多还原

【Abstract】 In the 21st century,the rapid development of human society has continuously increasing demand for resources.Thus,the development of new clean energy is essential.Organic-inorganic hybrid halide perovskite materials have become important materials for the development of clean energy due to their excellent optoelectronic properties,such as suitable bandwidth,strong light absorption capacity,and high carrier mobility,etc..At present,organic and inorganic perovskite materials have attracted broad attention in the field of solar cells.The perovskite solar cells have high photoelectric conversion efficiency and great application prospect,which can promote the sustainable development of human society.However,the quality of perovskite films plays a key role in the performance and life of solar cell devices.Among various optical thin film deposition technologies,pulsed laser deposition（PLD）technology has the advantages of easy operation and can be used to obtain the films of high quality.Therefore,in this thesis,the PLD technology is introduced to the preparation of inorganic perovskite thin films and applied to inorganic perovskite solar cells.The mainly completed two aspects of research work are as the following:1.PLD,instead of spin coating,was used to prepare CsPbBr₃ thin films,which were applied in perovskite solar cells.The CsPbBr₃ single crystal powders were synthesized by the solution method and then pressed into a target.The PLD technique was used to bombard the CsPbBr₃ target.The CsPbBr₃ thin film exhibited excellent fluorescence performance and maintained good stability in the high humidity environments.At the same time,during the process of preparing solar cells,we observed that the formed CsPbBr₃ plasma can penetrate into and be evenly distributed in the mesoporous Ti O₂ layer.Therefore,the effects of the thickness of mesoporous Ti O₂ and CsPbBr₃ films on the device performance were studied.The PCE of the best performance of the CsPbBr₃ perovskite solar cell reached 6.3%by continuously optimizing the thickness,the open circuit voltage was 1.37 V,the fill factor was72%,and the short-circuit current density was 6.4 m A/cm².2.Two-step method was applied to prepare CsPbBr_xI_3-x（x=0,1,2,3）films.Four targets were prepared using Cs Br,Cs I,PbB_r2,and PbI₂ as starting raw materials.CsPbBr_xI_3-x（x=0,1,2,3）films can be formed on the substrates by placing the corresponding two targets into the chamber and ablating them in the corresponding order.The CsPbBr_xI_3-x（x=0,1,2,3）thin films prepared by the two-step method of pulsed laser deposition technology have precisely controlled thickness and excellent fluorescence performance.We tested the fluorescence performance of the prepared CsPbBr_xI_3-x（x=0,1,2,3）thin film,and observed that the half height width of the fluorescence peak for CsPbBr_xI_3-x（x=0,1,2,3）thin film was in the range of 18.9-40.8 nm,the peak position of the fluorescence spectrum can be tuned between 513 nm and 663 nm.The measured time-resolved fluorescence spectra were fitted and the decay time was 8.93 ns,15.59 ns,7.49 ns,and 14.07 ns for CsPbBr_xI_3-x（x=0,1,2,3）thin films,respectively.The high quality CsPbBr_xI_3-x（x=0,1,2,3）films prepared by PLD technology have the advantages of low cost,simple operation and excellent photoelectric performance,can be applied to inorganic perovskite solar cells,optoelectronic devices and other fields,etc..更多还原