高效稳定平面异质结钙钛矿太阳电池的研究

发布时间：2018-05-12 01:22

本文选题：钙钛矿太阳电池 + 平面异质结　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：钙钛矿太阳电池因具有较高的光电转换效率、简单的制备流程、原材料廉价等优势,在相关领域的学术圈引起了研究热潮。钙钛矿层位于电子传输层和空穴传输层之间,形成三明治结构,电子和空穴分别在钙钛矿与两个传输层的接触界面进行传输。FTO上使用空穴传输材料PEDOT:PSS作为空穴传输层可得到高的功函数,使空穴的传输效率得到提升。但PEDOT:PSS自身也存在缺点,例如PEDOT:PSS的功函数与常用的钙钛矿材料CH3NH3PbI3的HOMO能级存在着0.3 eV左右的差距,因此会造成一定能量的流失。另外PEDOT:PSS有较强的酸性和吸湿性,会对器件的长期稳定性造成负面的影响。本文的相关研究工作主要通过使用添加剂或者额外的空穴传输材料来优化PEDOT:PSS作为空穴传输层的性能,以使平面异质结钙钛矿太阳电池的性能得到优化。具体研究如下:1、在反向结构p-i-n型的平面异质结钙钛矿太阳电池中,将自身具有高的功函数的金属氧化物氧化钨(WOx)插入到PEDOT:PSS和FTO之间,形成WOx/PEDOT:PSS复合空穴传输层,这样既可以防止FTO与PEDOT:PSS直接产生接触,以解决腐蚀基底和吸湿性对钙钛矿层产生影响的问题,又能一定程度上减小薄膜接触界面的势垒,使器件的性能得到优化。本项工作研究了额外加入WOx作为空穴传输层对薄膜的透光率、钙钛矿层的表面形貌、钙钛矿晶体质量、光电性能及长期稳定性等相关方面的作用。使用WOx/PEDOT:PSS作为复合空穴传输层的平面异质结钙钛矿电池的光电效率可以达到12.96%,而PEDOT:PSS的器件效率为10.56%,相比较而言提升了22.7%,并且还提高了器件的长期稳定性。2、将全氟磺酸聚四氟乙烯(Nafion)掺入PEDOT:PSS改善空穴传输层的性能使钙钛矿太阳电池的性能得到优化。Nafion是由全氟化磺酸酯构成的一种优良的阳离子交换剂,具有优良的热稳定性和机械稳定性。FTO上使用空穴传输材料PEDOT:PSS作为空穴传输层可得到高的功函数,通过对PEDOT:PSS和Nafion共混,增大空穴传输层的粗糙度,从而增大活性层与其的接触面积,有利于载流子的传输,增大电流,从而提高器件性能。将Nafion掺入PEDOT:PSS作为空穴传输层的电池效率达到了15.11%,比作为基准进行对比的PEDOT:PSS的电池效率(11.91%)提升了26.9%。
[Abstract]:Perovskite solar cells have many advantages, such as high photoelectric conversion efficiency, simple preparation process, cheap raw materials and so on. The perovskite layer is located between the electron transport layer and the hole transport layer, forming a sandwich structure. Electron and hole transport on the interface between perovskite and two transport layers. Using hole transport material PEDOT:PSS as the hole transport layer can obtain high work function and improve the hole transport efficiency. However, there are some disadvantages in PEDOT:PSS itself. For example, the work function of PEDOT:PSS is about 0. 3 EV from the HOMO level of perovskite material CH3NH3PbI3, which will result in a loss of energy. In addition, PEDOT:PSS has strong acidity and moisture absorption, which will have a negative impact on the long-term stability of the device. In order to optimize the performance of planar heterojunction perovskite solar cells, the performance of PEDOT:PSS as the hole transport layer is optimized by using additives or additional hole transport materials. The specific research is as follows: 1. In p-i-n type planar heterojunction perovskite solar cells with reverse structure, the metal oxide tungsten oxide WOxs with high work function are inserted between PEDOT:PSS and FTO to form a WOx/PEDOT:PSS composite hole transport layer. In this way, the direct contact between FTO and PEDOT:PSS can be prevented, so as to solve the problem of the influence of corrosion substrate and moisture absorption on perovskite layer, and the barrier of contact interface of thin film can be reduced to a certain extent, and the performance of the device can be optimized. In this work, the effects of the addition of WOx as the hole transport layer on the transmittance of the thin film, the surface morphology of perovskite layer, the quality of perovskite crystal, the optical and electrical properties and the long-term stability of perovskite have been studied. The photovoltaic efficiency of planar heterojunction perovskite cells using WOx/PEDOT:PSS as the composite hole transport layer can reach 12.96 and the device efficiency of PEDOT:PSS is 10.560.This increases 22.7and 22.2 in comparison, and it also improves the long-term stability of the device. The performance of perovskite solar cells was optimized by adding PEDOT:PSS to improve the hole transport layer. Nafion is an excellent cationic exchange agent composed of perfluorinated sulfonic esters. High work function can be obtained by using hole transport material PEDOT:PSS as the hole transport layer. The roughness of the hole transport layer can be increased by blending PEDOT:PSS and Nafion. Thus, the contact area between the active layer and the active layer is increased, which is beneficial to the carrier transmission and current, thus improving the performance of the device. The efficiency of Nafion doped with PEDOT:PSS as the hole transport layer reached 15.11%, which was 26.910% higher than that of PEDOT:PSS (11.91%).
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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