有机钙钛矿CH3NH3PbI3晶体的合成及表征观察1

河南科技大学毕业设计（论文）

Synthesis and characterization of organic - inorganic perovskite

CH3NH3PbI3 crystal

Abstract

Since 2012, CH3NH3PbX3 perovskite as new photosensitive material for dye sensitized solar cells has become new research direction in the field of the solar cell materials in the world. Synthesis and characterization of CH3NH3PbI3 are studied in this paper.

First of all, methyl amine and hydriodic acid solution were mixed and stirred at 0 ℃for 2h. CH3NH3I was obtained after drying the mixed solution. Then, the CH3NH3I and PbI2 were put in butyl lactone solution to form a yellow transparent solution, which was heated at 100 ℃for 15 minutes to get the desired perovskite CH3NH3PbI3. The

thermogravimetric and heat change of yellow transparent solution were done by TG-DSC. The CH3NH3PbI3 crystal structure and surface morphology were characterized by X- ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that: perovskite

CH3NH3PbI3 formed at temperatures less than 167 ℃ and decomposed after the temperature over 167 ℃. Perovskite CH3NH3PbI3 shows black color and the crystalline structure of CH3NH3PbI3 at room temperature is tetragonal with unit cell parameters a=b=8.872A, c=12.637A. The perovskite CH3NH3PbI3 film has high density. Stability of perovskite CH3NH3PbI3 is poor. Black CH3NH3PbI3 in the air for a long time becomes into yellow. Instability of perovskite CH3NH3PbI3 is discussed, based on the thermodynamics

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河南科技大学毕业设计（论文）

关键词：Perovskite、CH3NH3PbI3、Crystalline structure、CH3NH3I 目录

第一章 绪 论 ...................................................................................................1

§1.1钙钛矿的晶体结构 ..............................................................................1

§1.1.1原始钙钛矿 ...............................................................................1 §1.1.2有机／无机杂化晶体 ...............................................................1 §1.1.3 有机／无机杂化CH3NH3PbI3的晶体结构 .............................2 §1.2 究背景及意义 .....................................................................................2

§1.2.1 CH3NH3PbX3钙钛矿电池 .........................................................2 §1.2.2 CH3NH3PbI3钙钛矿晶体 ..........................................................3 §1.3 CH3NH3PbI3钙钛矿的合成 .................................................................4

§1.3.1 ...................................................................................................4 §1.3.2 CH3NH3PbI3钙钛矿薄膜的合成方法 .......................................4 §1.4实验的主要研究内容与目的 ..............................................................5 第二章 实验过程 ...............................................................................................6

§2.1实验材料与设备 ..................................................................................6

§2.1.1实验材料及试剂 .......................................................................6 §2.1.2实验设备...................................................................................6 §2.2 实验方法和流程 .........................................................................6 §2.2.1试样准备...................................................................................7 §2.2.2 甲胺醇与氢碘酸的反应制备MAI ...........................................7

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河南科技大学毕业设计（论文）

§2.2.3 MAI与碘化铅的反应制备CH3NH3PbI3 ..................................8 §2.2.4 XRD试样制备 ..........................................................................8 §2.2.5 SEM试样的制备 ......................................................................8 §2.2.6 TG-DSC试样的观察 ................................................................8

第三章 实验结果和数据分析 .......................................................................... 10

§3.1 TG-DSC曲线分析 ............................................................................. 10 §3.2 XRD结果 .......................................................................................... 11 §3.3 SEM结果分析 .................................................................................. 13 §3.4 MAPbI3稳定性观察 .......................................................................... 14 第四章 分析与讨论 ......................................................................................... 16

§4.1 MAPbI3稳定性分析 .......................................................................... 16 §4.2 有效利用MAPbI3的几种建议 ......................................................... 17 结论 .................................................................................................................. 18 致 谢 ................................................................................................................ 19 参考文献 ........................................................................................................... 20

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河南科技大学毕业设计（论文）

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河南科技大学毕业设计（论文）

第一章 绪 论

§1.1钙钛矿的晶体结构

§1.1.1原始钙钛矿

钙钛矿指CaTiO3，化学式为CaTiO3、属立方晶系的氧化物。由俄国科学家佩罗夫斯基(

，Perovskite)发现，后以他的姓命名，钙钛矿的英文

名称为Perovskite。后来把类似与钙钛矿晶体结构的物质统称为钙钛矿[1]。

钙钛矿的结构一般用珂罗酊氯化银印相法可以测出，大部分钙钛矿是ABX3型立方空间群组成（维科夫位置1a）呈立方体晶形。在立方体晶体常具平行晶棱的条纹，系高温变体转变为低温变体时产生聚片双晶的结果[2]。

对称特点: 高温变体为等轴晶系，点群m3m,空间群Pm3m;在600℃以下转变为正交晶系，点群mmm,空间群Pcmm

晶胞参数: 高温变体a=3.85埃,Z=1;在600℃以下a=5.37埃b=7.64埃,c=5.44埃,Z=4

晶体结构: 在高温变体结构中，钙离子位于立方晶胞的中心，为12个氧离子包围成配位立方-八面体，配位数为12；钛离子位于立方晶胞的角顶，为6个氧离子包围成配位八面体，配位数为6[3]。

§1.1.2有机／无机杂化晶体

有机／无机杂化晶体是指由有机分子和无机分子组元在分子水平上组装形成的结构独特的材料。在该类材料中，有机阳离子一般为直链的烷烃基或芳香烃基胺、染料分子以及聚合物等；金属阳离子通常是二阶或三阶的过渡金属离子。有机和无机组元的选择范围较大，组元变化会对杂合物的结构产生影响，结构变化必然会影响分子内部结合状态、能带结构等的变化，从而对材料的热稳定性、光学性能及电学性能等产生影响[4]。

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