A density functional study of structural, electronic and optical properties of titanium dioxide: Characterization of rutile, anatase and brookite polymorphs
A density functional study of structural, electronic and optical properties of titanium dioxide: Characterization of rutile, anatase and brookite polymorphs
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DOI：
10.1016/j.mssp.2014.12.027
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发表时间：
2015-03-01
影响因子：
4.1
通讯作者：
Hussain, R.
中科院分区：
文献类型：
--
作者：
Mohamad, Mazmira;Haq, Bakhtiar Ul;Hussain, R.
研究二氧化钛的基本物理性质对于确定其在不同领域的应用潜力是至关重要的，如电子禁带能的研究是将其开发用于光电子学和太阳能电池技术的关键。本文采用WIEN2k封装中实现的全势(FP)线性化(L)增广平面波加局域轨道(APW+LO)方法，在密度泛函理论(DFT)框架下，对金红石型、锐钛矿型和板钛矿型二氧化钛的结构、电学和光学性质进行了研究。为了将交换关联(XC)能量泛函/势部分纳入总能量中，在PW-LDA、PBE-GGA、WC-GGA、EV-GGA和MBJ-GGA水平上进行了计算，这些变量被用作本工作的操纵变量。从我们的计算中得到的结构参数结果与现有的实验结果是一致的。电子能隙结构分析表明，在这三种相中，二氧化钛都是半导体材料，而费米能级附近的带隙特征对于锐钛矿相是间接的，对于金红石相和板钛矿相是直接的。态密度(DOS)谱表明，O2p和Ti3d在导电区和价带区有很大程度的杂化，说明TiO2p和Ti3d之间存在很强的相互作用。此外，我们对其光学性质的研究也证实了从价带中的O2p到导带中的Ti3d的带间跃迁。(C)2014爱思唯尔有限公司。保留所有权利。
Study of fundamental physical properties of titanium dioxide (TiO2) is crucial to determine its potential for different applications, such as study of electronic band gap energy is essential to exploit it for optoelectronics and solar cell technology. We present here investigations pertaining to structural, electronic and optical properties of rutile, anatase and brookite polymorphs of TiO2 by employing state of the art full potential (FP) linearized (L) augmented plane wave plus local orbitals (APW+lo) approach realized in WIEN2k package and framed within density functional theory (DFT). To incorporate exchange correlation(XC) energy functional/potential part into total energy, these calculations were carried out at the level of PW-LDA, PBE-GGA, WC-GGA, EV-GGA, and mBJ-GGA which are exploited as the manipulated variables in this work. From our computations, the obtained structural parameters results were found to be consistent with the available experimental results. The analysis of electronic band gap structure calculations point to TiO2 as a semiconducting material in all three phases, whereas band gap character around Fermi level was found to be indirect for anatase, and direct for rutile and brookite phases. Density of state (DOS) profiles showed a substantial degree of hybridation between O 2p and Ti 3d in conduction and valence band regions, illustrating a strong interaction between Ti and O atoms in TiO2 compund. In addition, our investigations of the optical properties also endorse the interband transitions from O 2p in valence band to Ti 3d in conduction band. (C) 2014 Elsevier Ltd. All rights reserved.