有机无机杂化钙钛矿型太阳能电池的研究

发布时间：2018-03-24 01:20

本文选题：CH_3NH_3PbI_3薄膜　切入点：太阳能电池　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：有机/无机杂化钙钛矿太阳能电池由于具有光电转换效率高、成本低、制备工艺简单等优势成为近几年光伏领域的研究热点。自2009年问世以来,钙钛矿电池取得了飞速的发展。但由于研究时间短,仍有一些问题需要深入研究。首先,钙钛矿材料的可控制备仍是一个挑战,其反应动力学机制尚不明确;其次,钙钛矿电池展现出有别于传统光伏器件的输运行为,例如迟滞效应,光照预处理对器件输出性能的影响等等,其物理机制还不清楚;第三,如何改善载流子的抽取速率,进而提高柔性钙钛矿太阳电池的光电转换效率还有待深入研究。针对上述问题,本论文开展以下几方面的研究工作:(1)通过调节两步浸泡法中CH_3NH_3I溶液的浓度、浸泡温度、浸泡时间,有效调控了CH_3NH_3I在PbI_2中的扩散行为、成核密度和反应速率,进而实现了对薄膜晶粒尺寸、形貌和相纯度的调控,并系统分析了其反应动力学机制。利用优化后的工艺参数即CH_3NH_3I溶液浓度为10mg/ml,浸泡时间为10min,制备的CH_3NH_3PbI_3薄膜作为光吸收层应用在太阳能电池中,获得了11%的光电转换效率;(2)利用两步旋涂法制备CH_3NH_3PbI_3薄膜,并系统分析了CH_3NH_3I浓度对薄膜的结晶性能、表面形貌以及光吸收性能的影响。结果表明,当CH_3NH_3I浓度为70mg/ml时,CH_3NH_3PbI_3薄膜表面致密平整、相纯度高,以此为光吸收层制备的太阳能电池的光电转换效率达到12.3%;(3)系统研究了光照预处理对钙钛矿电池输出性能的影响,发现最初3min之内光照预处理可以显著提高器件的输出性能,但延长光照时间到7min之后电池的效率开始降低。利用离子移动的观点对上述光致输运特性进行了初步的机理分析。(4)通过改进后的两步旋涂法,即在CH_3NH_3I溶液中加入微量的DMF,在柔性PET基底上首次成功生长了一维CH_3NH_3PbI_3纳米线,与常规CH_3NH_3PbI_3薄膜相比,CH_3NH_3PbI_3纳米线与Zn O形成界面后,表现出更快的电子抽取速率,为提高柔性钙钛矿电池的光电转换效率提供了新思路。
[Abstract]:Organic / inorganic hybrid perovskite solar cells have become a research hotspot in photovoltaic field in recent years due to their advantages of high photoelectric conversion efficiency, low cost and simple preparation process. Perovskite batteries have made rapid development. However, due to the short research time, there are still some problems to be further studied. Firstly, the controllable preparation of perovskite materials is still a challenge, and the reaction kinetics mechanism is not clear. The physical mechanism of perovskite cells is not clear, such as hysteresis, the effect of light pretreatment on the output performance of photovoltaic devices, and so on. Thirdly, how to improve the decimation rate of carriers. In order to improve the photoelectric conversion efficiency of flexible perovskite solar cells, further research is needed. In view of the above problems, the following research work is carried out in this paper: 1) by adjusting the concentration of CH_3NH_3I solution and soaking temperature in two-step immersion method, The diffusion behavior, nucleation density and reaction rate of CH_3NH_3I in PbI_2 were effectively controlled by soaking time, and then the grain size, morphology and phase purity of the films were regulated. The mechanism of reaction kinetics was systematically analyzed. The optimized process parameters, namely, the concentration of CH_3NH_3I solution was 10 mg / ml, the immersion time was 10 min, and the prepared CH_3NH_3PbI_3 thin film was used as optical absorption layer in solar cells. CH_3NH_3PbI_3 thin films were prepared by two-step spin coating method. The effects of CH_3NH_3I concentration on the crystalline properties, surface morphology and optical absorption properties of the films were systematically analyzed. When the concentration of CH_3NH_3I is 70mg/ml, the surface of Ch _ S _ 3NH _ 3PbI _ 3 thin film is compact and smooth, and the phase purity is high. The photovoltaic conversion efficiency of solar cell prepared by using this method as the optical absorption layer is 12.3and (3) the effect of light pretreatment on the output performance of perovskite cell has been studied. It is found that the initial illumination pretreatment within 3min can significantly improve the output performance of the device. However, the efficiency of the cell began to decrease after prolonging the illumination time to 7min. A preliminary mechanism analysis of the photoinduced transport characteristics mentioned above was carried out by using the viewpoint of ion movement. The improved two-step spin coating method was used to analyze the mechanism of the phototransport characteristics. In other words, the one-dimensional CH_3NH_3PbI_3 nanowires were successfully grown on the flexible PET substrate by adding a small amount of DMFs in the solution. Compared with the conventional CH_3NH_3PbI_3 films, the interface between CHS _ 3NH _ 3PbI _ 3 nanowires and Zn-O showed a faster electron extraction rate. It provides a new idea for improving the photoelectric conversion efficiency of flexible perovskite battery.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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