【作者】 李海涛；

【导师】 陈永生；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2018， 硕士

【摘要】 近年来,以碘化铅甲胺(MAPb I3)为代表的有机-无机杂化钙钛矿太阳电池(PSCs)最高转换效率已超过22%,可媲美于多晶硅太阳电池。然而,PSCs中使用的有机空穴传输材料(HTMs)价格昂贵、空穴迁移率较低、稳定性较差,不利于PSCs的产业化发展。采用无机HTMs可进一步降低电池的成本,并提高电池的稳定性。常见的无机HTMs主要有氧化镍(Ni O)、硫氰酸亚铜(Cu SCN)、碘化亚铜(Cu I)、氧化亚铜(Cu2O)等。其中Cu2O具有储量丰富、空穴迁移率高等优势。同时,钙钛矿作为PSCs的核心层,其质量的高低直接影响着器件性能的优劣。本文对p型Cu2O薄膜的制备及MAPb I3薄膜的优化进行了研究,并构筑了反型平面PSCs,主要内容包括以下几个方面:(1)Cu2O薄膜的制备及在PSCs中的应用。由于热解作用,通过电子束直接蒸发沉积的薄膜为Cu2O和Cu的混合物;在空气中退火时,随着退火温度的升高,由于氧化作用,薄膜的组分由混合物先转变为纯的Cu2O,再转变为纯的氧化铜(Cu O)。当退火温度在100~150℃范围时,可得到平整、均匀致密、无孔洞的Cu2O薄膜,平均透过率达70%,光学带隙约为2.5 e V,HOMO能级位置约为-5.32 e V,电阻率约为5×103?·cm,霍尔迁移率约为30 cm2 V-1 s-1。应用于反型平面PSCs,在Cu2O薄膜厚度约为40 nm时,获得6.84%的最高效率。低于以PEDOT:PSS为HTMs的器件,这主要是由于钙钛矿前驱液在Cu2O薄膜上的润湿性较差,吸收层形成大量微孔洞,使漏电流增加所致。然而,当采用氧化亚铜/聚3,4-乙撑二氧噻吩:聚苯乙烯磺盐酸(Cu2O/PEDOT:PSS)双HTMs设计时,由于PEDOT:PSS对Cu2O具有较强的腐蚀作用,使电池性能恶化。(2)MAPb I3薄膜的一步法制备与优化。当在MAPb I3前驱液中加入一定量的甲胺(MA0)乙醇溶液,可以有效降低前驱液配比失衡,抑制MAPb I3薄膜中空位缺陷的形成,并提高结晶质量;当MA0乙醇溶液加入量为40μl/ml时,PSCs效率由8.17%提高到9.86%。在使用溶剂退火法制备MAPb I3薄膜时,滴加温度对MAPb I3薄膜的形貌和性能具有较大影响。在100℃时,滴加10μl二甲基甲酰胺(DMF),随后退火10 min制备的MAPb I3薄膜颗粒尺寸更大,质量更高,将其用于PSCs,效率提升至11.2%。(3)气相辅助溶液法制备MAPb I3薄膜。用快速升温管式炉进行该实验时,可以在较低的温度、较短的时间内制备出大颗粒尺寸、致密、均匀的MAPb I3薄膜。但是颗粒之间存在明显的晶界,且薄膜具有低的择优生长取向和荧光发光强度,说明薄膜结晶质量差和缺陷密度高。当薄膜经过MA0气体处理后,可在一定程度上改善薄膜的性能。更多还原

【Abstract】 In recent years,the highest conversion efficiency of organic-inorganic hybrid perovskite solar cells（PSCs）represented by CH₃NH₃PbI₃（MAPbI₃）has exceeded 22%,which is comparable to that of polysilicon solar cells.However,the hole transporting materials（HTMs）used in PSCs are expensive,hole mobility is low and stability is poor,which is not conducive to the industrial development of PSCs.The use of inorganic HTMs can furtherly reduce the cost and improve the stability of the battery.The main inorganic HTMs are NiO,CuSCN,CuI,Cu2O and so on.Among them,Cu2O has the advantages of abundant reserves and hole mobility is high.At the same time,perovskite as the core layer of PSCs,the quality of which directly affects the performance of the device.In this paper,the preparation of p-type Cu₂O thin film and the optimization of MAPbI₃ thin film were studied,and the inversion plane PSCs were constructed.This article mainly focuses on the following aspects:（1）The preparation of Cu₂O film and its application in PSCs.Due to pyrolysis,the film deposited by direct electron beam evaporation are mixtures of Cu₂O and Cu.When annealed in the air with the increase of annealing temperature,the composition of the film changed to pure Cu₂O from mixture and then to pure CuO due to oxidation.When the annealing temperature is in the range of 100¹50°C,a smooth,uniform and non porous Cu₂O film can be obtained,and the average transmission rate of which is70%,the optical band gap is about 2.5 eV,and the HOMO level is about-5.32 eV,and the resistivity is about 5×10³?·cm,and the Hall mobility is about 30 cm² V^-1 s^-1.Applied to inverted plane PSCs,the highest efficiency achieving 6.84%when the thickness of Cu₂O film is about 40 nm.But the efficiency is lower than that of PEDOT:PSS as HTMs.This is mainly due to the poor wetting of perovskite precursor in the Cu₂O film,and has a large number of microporous holes in the absorption layer,which increase the leakage current.However,when Cu₂O/PEDOT:PSS double-HTMs are used,the performance of the battery deteriorated because PEDOT:PSS has a strong corrosive action on Cu₂O.（2）One step preparation and optimization of MAPbI3 thin film.When a certain amount of methylamine（MA⁰）ethanol solution is added to the precursor of perovskite,the imbalance of the ratio of the precursor solution can be effectively reduced,and the formation of the defects in the MAPbI3 film can be suppressed and the quality of the crystallization can be improved.When the amount of MA⁰ ethanol solution added to40μl/ml,the efficiency of PSCs increased from 8.17%to 9.86%.When MAPbI₃ thin film were prepared by solvent annealing,dropping temperature had a great influence on the morphology and properties of it.When the 10μl DMF was added at 100°C,and the MAPbI₃ thin film prepared after annealing for 10 min had larger particle size and higher quality,when used in PSCs,the efficiency increased to 11.2%.（3）The preparation of MAPbI₃ thin film by Vapor-assisted solution.When the experiment is carried out in a rapid-rising tube furnace,a large particle size,dense and uniform MAPbI3 thin film can be prepared at a lower temperature in a shorter time.However,there is a clear grain boundary between the particles,and the thin film has a low preferred growth orientation and fluorescence intensity,indicateing that the quality of the film is poor and the defect density is high.When the film is treated with MA⁰gas,the performance of the film is improved to a certain extent.更多还原