硫氰酸盐在甲脒钙钛矿薄膜制备中的应用

发布时间：2018-05-05 10:31

本文选题：钙钛矿太阳能电池 + 甲脒　；参考：《浙江大学》2017年硕士论文

【摘要】：拟卤素硫氰酸根SCN-离子的引入有利于提高钙钛矿太阳电池的性能。在CH3NH3PbI_3(MAPbI_3)钙钛矿体系中,引入硫氰酸铅(Pb(SCN)_2)将形成层状二维钙钬矿(MA)2Pb(SCN)_2I2。在MAPbI_3钙钛矿薄膜的制备中,微量的Pb(SCN)_2也能有效提高MAPbI_3薄膜质量和电池的性能。目前,关于硫氰酸根(SCN-)的研究仅限于MAPbI_3钙钛矿。基于此,本论文以两种硫氰酸盐Pb(SCN)_2及NH_4SCN为研究对象,研究其在甲脒钙钕矿薄膜的制备及其对相应钙钛矿太阳电池性能的影响。我们首先将NH_4SCN应用到FAPbI_3薄膜的一步法制备中。NH_4SCN能够抑制黄色非钙钬矿相δ-FAPbI_3的形成,并提高黑色钙钬矿相α-FAPbI_3的结晶性。30 mol%的NH_4SCN使FAPbI_3薄膜为纯α相,增大晶体尺寸并改善薄膜形貌,使得FAbI3薄膜具有更好的湿稳定性。30mol%的NH_4SCN将一步法制备的FAPbI_3太阳电池的效率由普通的5.94%提高到11.44%,同时也提高了电池的稳定性。采用溶剂蒸发法成功制备了含有SCN-离子的三维钙钬矿FAPbI_3-x(SCN)x粉末,其晶体结构与α-FAPbI_3相同,在常温下会转变为δ相的橙红色粉末。在此过程中,NH_4SCN已不是充当添加剂的角色,而是替换I-离子形成三维钙钛矿。旋涂法与溶剂蒸发法制备的钙钛矿组分不同,说明了不同制备条件与方法将影响最终得到钙钛矿的成分。在FAPbI_3薄膜的两步法制备中,使用Pb(SCN)_2对PbI_2进行掺杂。少量的Pb(SCN)_2能显著增强FAPbI_3晶体的结晶性,并增大FAPbI_3的晶体尺寸。同时,Pb(SCN)_2的加入使FAPbI_3薄膜更加光滑,提高了 FAPbI_3钙钛矿太阳电池的效率。然而,随着Pb(SCN)_2掺杂比例的增大,FAPbI_3薄膜中PbI_2含量逐渐增多,过多的Pb(SCN)_2反而降低了电池的性能。Pb(SCN)_2的掺杂量为5%时,FAPbI_3钙钛矿太阳电池效率提升最明显,由原来的10.6%提高到13.3%。采用性能较好的FA-MA混合钙钛矿MA0.6FA0.4PbI_3体系,进一步对NH_4SCN在其薄膜的两步法制备中的作用进行研究。随着NH_4SCN量的增加,MA0.6FA0.4PbI_3钙钛矿的结晶性逐渐增强。同时,NH_4SCN能有效增大MA0.6FA0.4PbI_3钙铁矿晶体尺寸并降低薄膜的表面粗糙度。当NH_4SCN的添加量为2.5%时,PVSCs具有最高的效率16.0%。本论文探究了 SCN-在甲脒钙钬矿及混合钙钬矿制备中的作用,得到新的甲脒钙钕矿FAPbI_3-x(SCN)x,同时扩展了甲脒钙钛矿薄膜的制备方法。这对于推动甲脒钙钛矿太阳电池及新钙钬矿材料的发展具有重要的意义。
[Abstract]:The introduction of halogen thiocyanate (SCN-) ion can improve the performance of perovskite solar cells. In the Ch _ 3NH _ 3PbI _ 3 / MAPbI _ 3) perovskite system, the introduction of lead thiocyanate (Pb _ (2) SCN _ (2) will result in the formation of layered two-dimensional calcium and holmium ore (MA2PbSCN ~ (2). In the preparation of MAPbI_3 perovskite thin films, a small amount of Pb(SCN)_2 can also improve the quality of MAPbI_3 thin films and the performance of the batteries. At present, the study of SCN is limited to MAPbI_3 perovskite. Based on this, two kinds of thiocyanate Pb(SCN)_2 and NH_4SCN were studied in this paper, and their effects on the properties of perovskite solar cells were studied. We first applied NH_4SCN to the one-step preparation of FAPbI_3 thin films. NH _ 4SCN could inhibit the formation of 未 -FAPbI3, and increase the crystallinity of 伪 -FAPbI3 by increasing the crystallinity of 伪 -FAPbI3 in black calcium and holmium ore phase. 30 mol% NH_4SCN could make FAPbI_3 thin films pure 伪 phase, increase the crystal size and improve the morphology of FAPbI_3 films. The FAbI3 film has better wet stability. 30 mol% NH_4SCN can improve the efficiency of FAPbI_3 solar cells prepared by one-step method from 5.94% to 11.44%, and also improve the stability of FAPbI_3 solar cells. Three-dimensional calcium holmium ore FAPbI_3-x(SCN)x powder containing SCN- ion was successfully prepared by solvent evaporation method. The crystal structure of the powder is the same as 伪 -FAPbI _ 3, and can be transformed into a 未 -phase orange-red powder at room temperature. In the process, NH4SCN is not used as additive, but instead of I- ion to form three-dimensional perovskite. The composition of perovskite prepared by spin-coating method and solvent evaporation method is different, which indicates that different preparation conditions and methods will affect the final perovskite composition. In the preparation of FAPbI_3 thin films by two-step method, Pb(SCN)_2 was used to doped PbI_2. A small amount of Pb(SCN)_2 can significantly enhance the crystallinity of FAPbI_3 crystal and increase the crystal size of FAPbI_3. At the same time, the addition of PBX / SCN / 2 makes the FAPbI_3 thin film smoother and improves the efficiency of FAPbI_3 perovskite solar cells. However, with the increase of Pb(SCN)_2 doping ratio, the content of PbI_2 in the FAPbI3 thin film increases gradually, too much Pb(SCN)_2 decreases the performance of the battery. The doping amount of PbPbI3 is 5 and the efficiency of the FAPbI3 perovskite solar cell increases most obviously, from 10.6% to 13.33. The role of NH_4SCN in the two-step preparation of FA-MA thin films was studied by using FA-MA mixed perovskite MA0.6FA0.4PbI_3 system with better performance. The crystallinity of MA0.6FA0.4PbI3 perovskite increases with the increase of NH_4SCN content. At the same time, NH4SCN can effectively increase the crystal size of MA0.6FA0.4PbI_3 calcium iron ore and reduce the surface roughness of the film. When the amount of NH_4SCN added is 2.5, it has the highest efficiency of 16.0. In this paper, the role of SCN- in the preparation of formamidine calcium holmium ores and mixed calcium holmium ores has been investigated. A new formamidine calcium neodymium ore FAPbI 3-x SCNX has been obtained, and the preparation method of formamidine perovskite films has been expanded. It is of great significance to promote the development of formamidine perovskite solar cells and new calcium holmium ore materials.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2

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