Abstract: Poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS) which is a kind of conductive polymer with superior electrical conductivity and excellent flexibility, has great potential in the field of wearable solar cells. At present, more and more people are focusing on the application research of flexible solar cells in wearability, so as to solve a series of problems about flexible solar cells, including flexibility, specific power, portability and compatibility. PEDOT:PSS, as electrode and hole transport layer, plays an important role in the research of different flexible solar cells, which promotes the rapid development of flexible solar cells.
As an electrode, PEDOT:PSS plays a different role in DSSCs, OSCs, PSCs, and the modification methods are also slightly different. In DSSCs, PEDOT:PSS has high room temperature conductivity and remarkable stability, which can catalyze the I^3-/I^- redox reaction in solar cells. In terms of performance improvement, doping-based research ideas have been formed. The preparation process is simple, non-toxic, environmentally friendly and involve excellent electrocatalytic activity. In OSCs, the emergence of PEDOT:PSS can replace the traditionally expensive ITO, and the non-conductive component PSS in the polymer can be removed by solvent post-treatment and other methods, which significantly improves the conductivity of the PEDOT:PSS electrode. In PSCs, PEDOT:PSS can be used as a transparent substrate electrode and a top electrode of flexible PSCs, respectively. After further modification of PEDOT:PSS by doping or post-treatment, the conductivity of PEDOT:PSS as a conventional electrode is further improved, and its optical transmittance is further enhanced as a top electrode, which enables the performance of the battery device to ensure a high energy conversion efficiency. In terms of flexibility, compared with the traditional battery devices constructed by metal electrodes or ITO electrodes, the devices constructed by modified PEDOT:PSS can still maintain a level comparable to the initial efficiency after bending for hundreds of times, which provides a new idea for the development of efficient and stable flexible optoelectronic devices.
As a hole transport layer, PEDOT:PSS is only used in OSCs and PSCs due to the different structures of solar cells. In OSCs, PEDOT:PSS has a wide range of advantages as a hole transport layer. Its solution processing characteristics make it suitable for large-scale production, and it has excellent performance in smoothing electrode interface and extracting holes. Post-treatment or doping is often used to solve the problem that the strong acidity of PEDOT:PSS leads to the low efficiency of the battery. On the one hand, the acidity of PEDOT:PSS is reduced, and on the other hand, the electrochemical and optical properties of PEDOT:PSS can be improved, thus greatly improving the efficiency of OSCs. In PSCs, PEDOT:PSS is widely used as hole transport layer materials due to its matching energy level with perovskite and suitable conductivity, and simple preparation at low temperature. After doping-based modification, the energy level between PEDOT:PSS and perovskite is more matched, the carrier mobility and hole extraction ability are improved, and the efficiency of PSCs is significantly improved. Through the optimization of the preparation process, the stability and mechanical flexibility are also well balanced, which makes flexible wearable PSCs possible.
For flexible wearable solar cells, there are two primary problems: how to prepare high-efficiency and high-flexibility battery devices, and how to improve the stability of the battery while maintaining high efficiency and high flexibility. The application of PEDOT:PSS as electrode and hole transport layer in different flexible solar cells is becoming increasingly extensive. Researchers have continuously improved and optimized the electrode materials of flexible solar cells by such methods as doping, post-processing and so on. In these solutions, PEDOT:PSS has also made an irreplaceable contribution to the development of flexible solar cells, which is of far-reaching significance.

Key words: flexible solar cells, poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS), electrode, hole transport layer, doping

摘要： 新一代柔性高效太阳能电池将太阳能转换成电能,并具备质轻、可溶液加工等特点,为柔性可穿戴电子供能,在可穿戴领域潜力巨大。聚(3,4-乙撑二氧噻吩):聚苯乙烯磺酸(Poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid, PEDOT:PSS)是一种典型的导电高聚物,具备高导电性能、高透明性、强机械柔性等特点,在柔性太阳能电池中应用广泛,也是影响柔性太阳能电池性能的关键因素之一。本文综述了PEDOT:PSS作为电极、空穴传输层在柔性太阳能电池中的研究现状,总结提升PEDOT:PSS相关性能的方法,并对柔性太阳能电池的发展方向与发展前景进行了展望。

关键词: 柔性太阳能电池, 聚(3,4-乙撑二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS), 电极, 空穴传输层, 掺杂