Lehrstuhl für Theoretische Physik, Universität Paderborn, Paderborn, Germany.
J Phys Condens Matter. 2012 May 16;24(19):195503. doi: 10.1088/0953-8984/24/19/195503. Epub 2012 Apr 19.
In this study, we present a combined density functional theory and many-body perturbation theory study on the electronic and optical properties of TiO(2) brookite as well as the tetragonal phases rutile and anatase. The electronic structure and linear optical response have been calculated from the Kohn-Sham band structure applying (semi)local as well as nonlocal screened hybrid exchange-correlation density functionals. Single-particle excitations are treated within the GW approximation for independent quasiparticles. For optical response calculations, two-particle excitations have been included by solving the Bethe-Salpeter equation for Coulomb correlated electron-hole pairs. On this methodological basis, gap data and optical spectra for the three major phases of TiO(2) are provided. The common characteristics of brookite with the rutile and anatase phases, which have been discussed more comprehensively in the literature, are highlighted. Furthermore, the comparison of the present calculations with measured optical response data of rutile indicate that discrepancies discussed in numerous earlier studies are due to the measurements rather than related to an insufficient theoretical description.
在这项研究中，我们采用密度泛函理论和多体微扰理论相结合的方法，研究了 TiO(2)板钛矿以及四方相金红石和锐钛矿的电子和光学性质。电子结构和线性光学响应是通过 Kohn-Sham 能带结构计算得到的，应用了（半）局部和非局部屏蔽混合交换相关密度泛函。单粒子激发是在 GW 近似下处理独立准粒子的。对于光学响应计算，通过求解库仑相关电子-空穴对的 Bethe-Salpeter 方程，包括了双粒子激发。在此方法基础上，提供了 TiO(2)三种主要相的带隙数据和光学谱。突出了板钛矿与金红石和锐钛矿相的共同特征，这些特征在文献中已经进行了更全面的讨论。此外，与金红石的测量光学响应数据的比较表明，在许多早期研究中讨论的差异是由于测量而不是与理论描述不足有关。
