【作者】 赵勇；

【导师】 梁春军；

【作者基本信息】 北京交通大学 ， 光学工程（专业学位）， 2015， 硕士

【摘要】 高效率的把太阳能转化为电能是解决人类能源危机最有效和最直接的途径之一,因而将太阳光转化成电能的光伏产业近年越来越受到人们的重视。薄膜太阳能电池由于其巨大的应用潜力和低廉的价格优势,近年来已成为人类应对能源危机开发利用清洁能源的研究热点,其中最具应用前景和代表性的是聚合物太阳能电池和钙钛矿太阳能电池。本论文的工作主要就聚3-己基噻吩：富勒烯(P3HT: PCBM)体系薄膜太阳能电池中活性层掺杂浓度对器件性能的影响和有机-无机卤化物钙钛矿体系中极性可变的光伏器件两方面工作展开研究：1.使用不同溶剂的活性层溶液和器件后退火处理来调控基于P3HT:PCBM体系的聚合物太阳能电池器件活性层的掺杂浓度,通过电容-电压测量、光学显微成像和MATLAB模拟计算研究了器件活性层掺杂浓度对器件性能的影响。研究结果表明活性层掺杂浓度和器件性能之间有着直接的联系,低掺杂浓度会使器件的短路电流升高,而使器件的开路电压下降。低掺杂浓度能够导致较宽的耗尽区,这有利于活性层中载流子的收集。实验数据和模拟计算的一致性很好的说明在聚合物太阳能电池中开路电压随着掺杂浓度的增加而线性增加。活性层表面形貌的变化说明无论是使用低沸点的溶剂使活性层缓慢干燥还是通过热退火增加P3HT和PCBM的结晶度和相分离,都能够减少活性层的缺陷密度从而降低其掺杂浓度。2.在有机-无机卤化物钙钛矿体系中通过新型结构ITO/PEDOT:PSS/CH3NH3PbI3/MoO3/Al实现了极性可变的光伏器件,该新结构极性可变的光伏器件为该领域的研究开辟了新的方向。通过该新型结构光伏器件的新特性发现和证明在有机-无机卤化物钙钛矿材料中存在大量可移动的离子。在外加电场的作用下移动离子在器件电极界面处的聚积使界面处的半导体材料钙钛矿界面处的能带发生弯曲,随着外加电场方向的不同半导体材料钙钛矿界面处聚积的电荷性极性也不同,其能带弯曲的方向也就不同,从而器件在相反方向的外加电场下极性就会反转。移动离子的存在对钙钛矿光伏器件的性能有着重要的影响,在电流-电压测量过程中的滞后现象就是由于移动离子在界面处的聚积和弛豫所引起的。更多还原

【Abstract】 High efficient convert solar energy into electricity is the most effective and direct way to solve the energy crisis, and photovoltaic industry increasingly get people’s attention in recent years. Thin film solar cells has become the hotspot to develop clean energy and solve the energy crisis due to its great application potential and low price advantage, organic polymer solar cells and perovskites solar cell are the most promising and representative. In this paper, the work mainly on the effect of detect density on device performance of polymer solar cells based on the system of poly (3, hexyl thiophene:fullerenes (P3HT:PCBM) and study on polarity-switchable perovskite photovoltaic devices:1. The change in doping density in P3HT:PCBM based polymer solar cells (PSCs) with different processing solvents and with/without post-fabrication thermal treatment is investigated with capacitance-voltage measurement and optical microscopic imaging. Direct links between the doping density and the performance of the PSCs, specifically the short-circuit current (Jsc) and open-circuit voltage (Voc), are observed. Lower doping density leads to a wider depletion region, which is beneficial for carrier collection. The agreement between the calculation and the experiment suggests that the Voc increases monotonically with increasing doping densities in the PSCs. Evolution in surface morphology suggests that both slow drying and thermal treatment facilitate the phase-separation and crystallinity of P3HT and PCBM, leading to low defect density and thus low p-type doping density.2. We developed an novel polarity-switchable photovoltaic device in the structure of ITO/PEDOT:PSS/CH3NH3PbI3/Mo03/Al. It is proved that a large amount of mobile ions exist in organic-inorganic halide perovskites. The accumulated ions at the interface change the band bending of the perovskites semiconductor, the change of bias’direction will change the polarity of accumulated ions at the interface, leading to polarity-switchable photovoltaic devices. The interface charge significantly influences the function and performance of perovskite devices. The current-voltage hysteresis in perovskite solar cells is caused by the accumulation and relaxation of the interface charge.更多还原