二硫化亚铁的能带结构与相对稳定性:GW方法与随机相位近似的第一性原理研究
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- 英文论文题名：Band Structure and Relative Stability of FeS_2 Polymorphs: a First-Principles Study Using GW and Random Phase Approximation
- 论文作者：张旻烨 ; 蒋鸿
- 英文论文作者：Min-Ye Zhang ; Hong Jiang ; College of Chemistry and Molecular Engineering ; Peking University
- 年：2016
- 作者机构：北京大学化学与分子工程学院;
- 论文关键词：二硫化亚铁 ; 电子能带结构 ; 热力学稳定性 ; GW方法 ; 随机相位近似
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十八分会：电子结构理论方法的发展与应用
- 语种：中文
- 分类号：O644.1
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十八分会 ; 电子结构理论方法的发展与应用
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：145k
- 原文格式：D
- 会议级别：全国
摘要
黄铁矿型二硫化亚铁因具有带隙合适(0.95 eV)、光吸收率高、无毒和廉价易获取的特点,在光伏太阳能电池、光电化学器件以及催化等方面具有巨大的应用潜力。而在理论计算方面,当前基于局域或半局域泛函的密度泛函理论方法对二硫化亚铁体系的解释存在两个难题:(1)理论预测带隙与实验测量带隙存在明显差异~1;(2)无法验证实验测定的二硫化亚铁的两种晶型——黄铁矿型和白铁矿型在常温下的热力学相对稳定性~2。本文尝试通过超越传统密度泛函理论的第一性原理方法,对上述问题进行研究。针对带隙问题,采用了基于格林函数多体微扰理论的GW方法,包括G_0W_0和GW_0,计算二硫化亚铁的准粒子能带结构。针对两种晶型的相对稳定性问题,一方面采用随机相位近似方法对密度泛函理论计算中的交换关联能进行校正,另一方面考察了基于谐振子近似的零点能效应和温度效应对晶相相对稳定性的贡献。
Iron pyrite(FeS_2) shows significant potential for applications in photovoltaic solar cells, photoelectrochemical devices and catalysis, due to its suitable band gap(0.95 eV), remarkable optical absorption, nontoxicity and accessibility.Regarding theoretical studies, density functional theory(DFT) based on local or semi-local functionals have confronted two major difficulties in tackling FeS_2 systems, which are(1) the apparent discrepancy between predicted band gap and the experiment value, and(2) the inability to fully account for the thermodynamic relative stability between two FeS_2 polymorphs, pyrite and marcasite.Here, first-principles calculations beyond DFT are performed to bring insights into the problems.The quasi-particle energies were calculated by the GW method(G_0W_0, GW_0) of many-body perturbation theory to address the band gap problem.For the relative stability problem, the DFT total energies are corrected by the zero-point energy of vibrations and random phase approximation, which treats the exchange-correlation energy more accurately.
Iron pyrite(FeS_2) shows significant potential for applications in photovoltaic solar cells, photoelectrochemical devices and catalysis, due to its suitable band gap(0.95 eV), remarkable optical absorption, nontoxicity and accessibility.Regarding theoretical studies, density functional theory(DFT) based on local or semi-local functionals have confronted two major difficulties in tackling FeS_2 systems, which are(1) the apparent discrepancy between predicted band gap and the experiment value, and(2) the inability to fully account for the thermodynamic relative stability between two FeS_2 polymorphs, pyrite and marcasite.Here, first-principles calculations beyond DFT are performed to bring insights into the problems.The quasi-particle energies were calculated by the GW method(G_0W_0, GW_0) of many-body perturbation theory to address the band gap problem.For the relative stability problem, the DFT total energies are corrected by the zero-point energy of vibrations and random phase approximation, which treats the exchange-correlation energy more accurately.
引文
[1]Sun,R.S.;Chan,M.K.Y.;Ceder,G.Phys.Rev.B 2011,83:235311.
[2]Spagnoli,D.;Refson,K.;Wright,K.;Gale,J.D.Phys.Rev.B 2010,81:094106.
[2]Spagnoli,D.;Refson,K.;Wright,K.;Gale,J.D.Phys.Rev.B 2010,81:094106.