层状C_2N体系电子结构和光学性质的GW+BSE的理论研究
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- 英文论文题名：A many-body GW+BSE investigation of electronic and optical properties of C_2N
- 论文作者：孙久雨 ; 张瑞奇 ; 李星星 ; 杨金龙
- 英文论文作者：Jiuyu Sun ; Ruiqi Zhang ; Xingxing Li ; Jinlong Yang ; Hefei National Laboratory for Physical Sciences at the Microscale ; University of Science and Technology of China ; International Center for Quantum Design of Functional Materials (ICQD) ; University of Science and Technology of China
- 年：2016
- 作者机构：中国科学技术大学合肥微尺度物质科学国家实验室;中国科学技术大学国际量子功能材料设计中心(ICQD);
- 论文关键词：二维材料 ; GW+BSE ; 激子效应
- 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-第四十分会：纳米体系理论与模拟
- 语种：中文
- 分类号：TB30
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十分会 ; 纳米体系理论与模拟
- 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：141k
- 原文格式：D
- 会议级别：全国
摘要
本文使用基于多体微扰理论的GW+BSE方法,对新近合成的二维层状材料C_2N[1]进行了理论研究。从单层到体相材料,C_2N电子带隙从3.74eV减小到1.89eV。格林函数GW方法得到的准粒子带隙相比于局域密度近似(LDA)大出多达0.9eV。在C_2N体系中,激子效应对于光学性质有着重要的作用。多层C_2N体系中,束缚激子的结合能至少达到0.6eV,而在体相体系中只有0.04eV。C_2N层状材料在可见光区均表现出很强的光吸收性质。这一特点让它有望成为太阳能利用的新材料,例如太阳能光解水。
A newly synthesized layered material C_2N was investigated based on manybody perturbation theory using GW plus Bethe-Salpeter equation approach. The electronic band gap was determined to be ranging from 3.75 to 1.89 e V from monolayer to bulk. Significant GW quasiparticle corrections, of more than 0.9 e V, to the Kohn-Sham band gaps from the local density approximation(LDA) calculations are found. Strong excitonic effects play a crucial role in optical properties. We found large binding energies of greater than 0.6 e V for bound excitons in few-layer C_2N, while it is only 0.04 e V in bulk C_2N. All the structures exhibit strong and broad optical absorption in the visible light region, which makes C_2N a promising candidate for solar energy conversion, such as photocatalytic water splitting.
A newly synthesized layered material C_2N was investigated based on manybody perturbation theory using GW plus Bethe-Salpeter equation approach. The electronic band gap was determined to be ranging from 3.75 to 1.89 e V from monolayer to bulk. Significant GW quasiparticle corrections, of more than 0.9 e V, to the Kohn-Sham band gaps from the local density approximation(LDA) calculations are found. Strong excitonic effects play a crucial role in optical properties. We found large binding energies of greater than 0.6 e V for bound excitons in few-layer C_2N, while it is only 0.04 e V in bulk C_2N. All the structures exhibit strong and broad optical absorption in the visible light region, which makes C_2N a promising candidate for solar energy conversion, such as photocatalytic water splitting.
引文
[1]Mahmood,J.;Lee,E.K.;Jung,M.;Shin,D.;Jeon,I.-Y.;Jung,S.-M.;Choi,H.-J.;Seo,J.-M.;Bae,S.Y.;Sohn,S.-D.et al.Nature Communications 2015,6:6486.