标题:
钙钛矿CH3NH3PbI3结构和电子性质的第一性原理研究First-Principles Study of Structural and Electronic Properties of Perovskite-Type CH3NH3PbI3
作者:
刘洪飞, 张众维
关键字:
第一性原理, CH3NH3PbI3, 电子性质First-Principles, CH3NH3PbI3, Electronic Properties
期刊名称:
《Applied Physics》, Vol.6 No.12, 2016-12-16
摘要:
我们采用基于密度泛函理论的第一性原理方法研究了钙钛矿CH3NH3PbI3材料的结构和电子性质。计算表明optB86b + vdWDF交换关联泛函给出的晶格结构和实验结果符合的很好。同时，能带结构分析表明材料是直接带隙材料，带隙宽度为1.68 eV与实验结果相符。态密度分析表明，价带顶和导带底分别是由I 5p轨道和Pb 6p轨道组成，而有机分子CH3NH3对于价带顶和导带底的贡献较小。这些结果说明，对于钙钛矿CH3NH3PbI3类材料，包含范德瓦尔斯作用的vdW-DF泛函能够更好的描述体系的物理性质。
Using first-principle calculations based on density functional theory (DFT), we have studied the structural and electronic properties of perovskite-type CH3NH3PbI3. The structural properties cal- culated by DFT with the optB86b + vdWDF exchange-correlation functional are in good agreement with experimental results. The band structures analysis shows that perovskite-type CH3NH3PbI3 is a direct band gap material. In addition, the calculated band gap, ~1.68 eV, is close to experimental results. The analysis of partial density of states shows that the top of valence band is mainly composed of I 5p states. And, the main components of the conduction bands bottom are Pb 6p states. In contrast, the organic CH3NH3 makes little contribution to the top valence and bottom conduction bands. Thus, consideration of the vdW interactions is important for theoretical studies of perovskite-type CH3NH3PbI3 material.