退火温度对CH3NH3PbI3钙钛矿薄膜结构和电学特性的影响  

Effect of annealing temperature on structural and electrical properties of CH_3NH_3PbI_3 thin films

作　　者：吴亚美 杨瑞霞[1] 田汉民[1] 陈帅[1] 

机构地区：[1]河北工业大学电子信息工程学院,天津市电子材料与器件重点实验室,天津300400

出　　处：《功能材料》2016年第7期7192-7196,共5页Journal of Functional Materials

基　　金：河北省自然科学基金资助项目(F2014202184);天津市自然科学基金资助项目(15JCZDJC37800)

摘　　要：采用一步溶液法制备的CH_3NH_3PbI_3薄膜,用扫描电子显微镜、原子力显微镜、X射线衍射仪对CH_3NH_3PbI_3钙钛矿薄膜的表面形貌和晶体结构进行表征。通过对薄膜的电流-电压(I-V)曲线的测试结果计算得到在退火温度为60,80,100,120和140℃制备的CH_3NH_3PbI_3薄膜的电导率分别为0.0069,0.0089,0.0178,0.0104和0.0013mS/cm。研究结果表明,合适的退火温度有助于薄膜结晶度的提高,晶粒尺寸的增大且尺寸分布均匀,从而有效减少晶界缺陷和晶界散射,薄膜电导率大幅度提高。但是,过高的退火温度(>120℃)会导致碘离子VI空位缺陷的数量急增,甚至导致CH_3NH_3PbI_3的分解,使得薄膜内部的缺陷浓度提高。由于缺陷散射增强,载流子迁移率降低,薄膜电导率减小。CH3NH3PbI3thin films are prepared by one-step solution deposition method and annealed at different temperatures（60,80,100,120,140℃）.Effect of annealing temperature on the surface morphology and crystalline structure of the prepared thin films are investigated by Scanning Electron Microscopy,Atomic Force Microscope and X-Ray Diffraction,respectively.From their current-voltage（I-V）curves,the conductivity of CH3NH3PbI3 thin film annealed at 60,80,100,120,and 140 ℃ are calculated as 0.0069,0.0089,0.0178,0.0104 and 0.0013mS/cm,respectively.It turns out that under suitable annealing temperature,the degree of crystallinity of the films was increased,and grain size distribution becomes more uniform.Therefore,the defects between adjacent grains and scattering caused by grain boundary were effectively decreased,leading to a great increase of conductivity.However,under high annealing temperature（〉120 ℃）,large numbers of VIvacancies were generated and fractions of CH3NH3PbI3 decompose,which eventually result in the decrease of carrier mobility.

关 键 词：钙钛矿 CH3NH3PbI3 太阳电池 退火温度 电导率 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TB34[一般工业技术—材料科学与工程]