钙钛矿太阳电池中新型电子传输层的设计和制备

发布时间：2018-01-09 01:06

本文关键词：钙钛矿太阳电池中新型电子传输层的设计和制备　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：具有钙钛矿结构的有机卤化铅材料具有溶液可加工性、载流子扩散距离大、光吸收范围宽等优势,组装的钙钛矿太阳电池已经成为极具潜力的光伏器件。相比于其他类型的太阳电池,钙钛矿太阳电池的制备过程对设备要求较低,有利于降低器件制备成本,目前效率已经超过20%,器件的稳定性研究也有一定的突破。在钙钛矿太阳电池中,电子传输层具有促进光生电子/空穴在界面分离、优化电子传输通道、抑制光生电子/空穴复合等作用,电子传输层的性质直接影响器件的性能和稳定性。本文将通过掺杂改性和界面处理两个方面展开钙钛矿太阳电池电子传输层的研究:1,CH_3NH_3PbI_3(MAPbI_3)是常用的钙钛矿太阳电池吸光材料,基于甲脒离子的有机碘化铅具有更宽的光吸收范围,是一种极有前景的吸光层材料,在这一研究中我们利用HC(NH2)2Pb I_3(FAPb I_3)制备了平面结钙钛矿太阳电池。平面结器件具有结构简单、迟滞效应低等优势,但对钙钛矿吸光层的质量要求比较高。在用两步法制备FAPb I_3时常常会出现针孔缺陷和黄色δ相,这些缺陷会导致内部的复合过程。在这项研究中,引入[6,6]-phenyl-C61-butyric acid methyl ester(PCBM)作为Ti O_2电子传输层与FAPb I_3层的过渡层。SEM图像表明PCBM过渡层能够促进FAPb I_3吸光层中晶粒的生长。XRD图谱表明PCBM层可以抑制黄色δ相的形成,并能增强钙钛矿晶体的结晶度。当PCBM前驱液浓度在最佳的情况下,可以使FAPb I_3平面结器件的平均太阳光转换效率从6.8%提高到15.1%,并且最优浓度下的器件迟滞效应很小。阻抗谱表明PCBM过渡层能有效的抑制器件内部载流子复合过程,进而提高了器件性能。2,TiO_2是钙钛矿太阳电池中广泛应用的电子传输层材料。可以通过掺入金属离子调控Ti O_2性能,以及优化Ti O_2/MAPb I_3界面。由于La元素电子未完全占据的4f或5d轨道,其配位作用有利于界面的紧密结合,另外,La的稳定价态是正三价,掺入Ti O_2中所产生的电荷补偿作用,有利于抑制光生电子/空穴的复合过程。我们通过喷雾热解的方法制备掺杂La的Ti O_2薄膜,作为钙钛矿器件的电子传输层。扫描电子显微镜(SEM)测量表明La的掺杂能使Ti O_2薄膜表面更平滑,抑制颗粒熟化过程。在最优化的掺杂浓度下,器件的平均效率从12.4%提高到14.4%,最高效率达到17.2%。阻抗测试表明,La掺杂可以降低界面电荷转移电子,并且可以有效提高复合电阻。此外我们还发现掺La的二氧化钛传输层能够抑制MAPb I_3吸光层的分解,从而提高器件的光稳定性。
[Abstract]:Organic lead halide with perovskite structure has the advantages of processability, large carrier diffusion distance and wide optical absorption range. The assembled perovskite solar cells have become potential photovoltaic devices. Compared with other types of solar cells, the preparation process of perovskite solar cells requires less equipment, which is beneficial to reduce the cost of device preparation. In perovskite solar cells, the electron transport layer promotes the separation of photogenerated electrons / holes at the interface and optimizes the electron transmission channels. The effect of photoelectron / hole recombination was inhibited. The properties of the electron transport layer directly affect the performance and stability of the device. In this paper, the electron transport layer of perovskite solar cells will be studied by doping modification and interface treatment. Ch _ 3NH _ 3PbI _ 3 is a commonly used photoabsorbent for perovskite solar cells, and organic lead iodide based on formamidine ion has a wider range of light absorption. Is a promising absorbent layer material. In this study, we have fabricated planar perovskite solar cells using HC(NH2)2Pb I _ S _ 3s _ 3 / FAPb / IP _ 3. The planar junction devices have the advantages of simple structure and low hysteresis effect. However, the quality of perovskite absorbent layer is very high. In this study, pinhole defects and yellow 未 phase often occur in the preparation of FAPb I _ 3 by two-step method. These defects will lead to the internal composite process. Introduction. [6. 6) -phenyl-C61-butyric acid methyl. As the transition layer between TiO2 electron transport layer and FAPb I3 layer, SEM images show that PCBM transition layer can promote FAPb. The growth of grains in the absorption layer of I _ 3. The XRD spectra show that the PCBM layer can inhibit the formation of yellow 未 -phase. The crystallinity of perovskite crystal can be enhanced when the concentration of PCBM precursor is optimal. The average solar light conversion efficiency of FAPb I _ 3 planar junction devices can be increased from 6.8% to 15.1%. And the hysteresis effect is very small at the optimal concentration. Impedance spectroscopy shows that the PCBM transition layer can effectively suppress the internal carrier recombination process, and then improve the device performance. 2. TiO_2 is a widely used electron transport layer material in perovskite solar cells. The performance of TiO_2 can be controlled by doping metal ions. And optimizing the interface of TIO _ 2 / MAPb _ I _ 3. Because of the 4f or 5d orbitals which are not completely occupied by the electrons of La element, the coordination action is advantageous to the close combination of the interfaces. The stable valence state of La is the charge compensation produced by doping TIO _ 2 in the normal trivalent state. We prepared La doped TIO _ 2 thin films by spray pyrolysis. As the electron transport layer of perovskite devices, scanning electron microscopy (SEM) measurements show that La doping can smooth the surface of TIO _ 2 thin films. The average efficiency of the device was increased from 12.4% to 14.4, and the maximum efficiency was 17.2. The impedance test showed that under the optimized doping concentration, the average efficiency of the device was increased from 12.4% to 14.4. La doping can reduce the interfacial charge transfer electrons and increase the composite resistance effectively. In addition, we also found that La doped titanium dioxide transport layer can inhibit the decomposition of MAPb ISt3 absorption layer. Thus, the optical stability of the device is improved.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

【参考文献】