摘要
采用低成本的气相辅助电沉积方法(vapor-assisted electro-deposition,VAED)成功制备了面积为15 cm~2均匀致密的钙钛矿薄膜。首先通过电化学沉积制备PbO_2薄膜,然后与HI气体反应得到PbI_2薄膜,接下来再与HI和CH3NH2混合气体反应,得到CH_3NH_3PbI_3薄膜。实验发现:电化学沉积电压对PbO_2薄膜的表面形貌和微结构有重要影响;在PbO_2向PbI_2的转化过程中,随着反应时间的减小,PbI_2的结晶性逐渐增强,最佳反应时间为10 min;在钙钛矿的转化过程中,当HI/CH_3NH_2体积比为1∶2时可获得均匀致密、四方相的钙钛矿薄膜。本研究提供了一种低温制备大面积均匀CH_3NH_3PbI_3薄膜的方法,得到的CH_3NH_3PbI_3薄膜可望在光电器件中得到应用。
A uniformly dense perovskite film with an area of 15 cm~2 was successfully prepared by low-cost vapor-assisted electro-deposition( VAED). Firstly,PbO_2 film was prepared by electro-deposition and then reacted with HI gas to obtain PbI_2 film,and then reacted with HI and CH3 NH2 mixed gas to obtain CH_3NH_3PbI_3 film. The experimental results show that the electro-deposition voltage had an important influence on the surface morphology and microstructure of PbO_2 films. During the conversion of PbO_2 to PbI_2,the crystallinity of PbI_2 gradually increased with the decrease of reaction time,and the optimum reaction time was 10 min; In the process of perovskite conversion,a uniform and compact perovskite film with cube phase can be obtained when the volume ratio of HI/CH_3NH_2 was 1 ∶ 2. This study provided a preparation method of large-area CH_3NH_3PbI_3 films in a low-temperature way, and the obtained CH_3NH_3PbI_3 thin films was expected to be used in optoelectronic devices.
引文
[1]Tan Z K,Moghaddam R S,Lai M L,et al.Bright Light-Emitting Diodes Based on Organometal Halide Perovskite[J].Nat.Nanotechnol.,2014,9(9):687-692.
[2]Cho H,Jeong S H,Park M H,et al.Overcoming the Electroluminescence Efficiency Limitations of Perovskite Light-Emitting Diodes[J].Science,2015,350(6265):1222-1225.
[3]Wu Y,Li J,Xu J,et al.Organic-Inorganic Hybrid CH3NH3Pb I3Perovskite Materials as Channels in Thin-Film Field-Effect Transistors[J].RSC Adv.,2016,6(20):16243-16249.
[4]Deschler F,Price M,Pathak S,et al.High Photoluminescence Efficiency and Optically Pumped Lasing in Solution-Processed Mixed Halide Perovskite Semiconductors[J].Phys.Chem.Lett.,2014,5(8):1421-1426.
[5]Moehl T,Im J H,Lee Y H,et al.Strong Photocurrent Amplification in Perovskite Solar Cells with a Porous Ti O2Blocking Layer under Reverse Bias[J].Phys.Chem.Lett.,2014,5(21):3931-3936.
[6]Lin Q,Armin A,Burn P L,et al.Filterless Narrowband Visible Photodetectors[J].Nat.Photonics,2015,9(10):687-694.
[7]Gu C,Lee J S,Flexible Hybrid Organic-Inorganic Perovskite Memory[J].ACS Nano,2016,10(5):5413-5418.
[8]Kojima A,Teshima K,Shirai Y,et al.Organometal halide perovskites as visible-light sensitizers for photovoltaic cells[J].Am.Chem.Soc.,2009,131(17):6050-6051.
[9]National Renewable Energy Laboratory.Best Research-Cell Efficiencies.Available online:https://www.nrel.gov/pv/assets/images/efficiencychart.png(accessed on 30 October 2017)
[10]王亚丽,王佳,侯丽新,等.钙钛矿吸光层薄膜制备工艺研究进展[J].信息记录材,2016,17(5):92-97.
[11]Edr Iie,Kirmayer S,Kulbak M,et al.Chloride inclusion and hole transport material doping to improve methyl ammonium lead bromide perovskitebased high open-circuit voltage solar cells[J].Phys.Chem.Lett.,2014,5(3):429.
[12]SoniaR,Raga,Luis K,et al.Rapid perovskite formation by CH3NH2-gas induced intercalation and reaction of Pb I2[J].Mater.Chem.A.,2016,4(7):2494.
[13]Li Xiong,Bi Dongqin,Yi Chenyi,et al.A vacuum flash-assisted solution process for high-efficiency large-area perovskite solar cells[J].Science,2016,353(6294):58-61.
[14]Chen Han,Ye Fei,Tang Wentao,et al.A solvent-and vacuum-free route to large-area perovskite films for efficient solar modules[J].Nature,2017,550(7674):92-95.
[15]Shin H C,Dong J,Liu M L.Porous tin Oxides prepared using an anodic Oxidation process[J].Adv.Mater.,2006,3(16):237-240.
[16]Schieber M,Zamoshchik N,Khakhan O,et al.Structural changes during vapor-phase deposition of polycrystalline-Pb I2films[J].Crystal Growth,2008,310(13):3168-3173.