期刊
JOURNAL OF PHYSICS COMMUNICATIONS
卷 1, 期 5, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/2399-6528/aa97c6
关键词
TiO2; high pressure; band gap; robustness; first-principles calculations
资金
- Institute of Solid State Physics (ISSP) of Chinese Academy of Sciences (CAS) [41]
- National Natural Science Foundation of China [11474285]
Titanium dioxide (TiO2) is a wide band gap semiconducting material which is promising for photocatalysis. Here we present first-principles calculations to study the pressure dependence of structural and electronic properties of two TiO2 phases: the cotunnite-type and the Fe2P-type structure. The band gaps are calculated using density functional theory with the generalized gradient approximation, as well as the many-body perturbation theory with the GW approximation. The band gaps of both phases are found to be unexpectedly robust across a broad range pressures. The corresponding pressure coefficients are significantly smaller than that of diamond and silicon carbide, whose pressure coefficient is the smallest value ever measured by experiment. The robustness originates from the synchronous change of valence band maximum and conduction band minimum with nearly identical rates of changes. A step-like jump of band gaps around the phase transition pressure point is expected and understood in light of the difference in crystal structures.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据