Predicting New TiO2 Phases with Low Band Gaps by a Multiobjective Global Optimization Approach

TiO2 has been extensively studied due to the possible application in solar cells and photoelectrochemical (PEC) water-splitting. However, the energy conversion efficiency is rather low because of the large band gaps (larger than 3.0 eV) of rutile and anatase TiO2. Here we introduce the multiobjectiv...

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Bibliographic Details
Published in:Journal of physical chemistry. C 2014-02, Vol.118 (5), p.2333-2337
Main Authors: Chen, Hou-Zun, Zhang, Yue-Yu, Gong, Xingao, Xiang, Hongjun
Format: Article
Language:English
Online Access:Get full text
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Summary:TiO2 has been extensively studied due to the possible application in solar cells and photoelectrochemical (PEC) water-splitting. However, the energy conversion efficiency is rather low because of the large band gaps (larger than 3.0 eV) of rutile and anatase TiO2. Here we introduce the multiobjective differential evolution (MODE) method as a novel global optimization algorithm to predict new polymorphs of bulk TiO2 with better optical properties than rutile and anatase TiO2. The band gaps of the new PI (Pnma) and CI (C2) phases are found to be 1.95 and 2.64 eV. The calculation of formation energy, phonon dispersions, and thermal stability shows that the two novel phases are dynamically and thermally stable. These new TiO2 polymorphs with better electronic and optical properties may pave a new way for high-efficiency solar energy conversion.
ISSN:1932-7447
1932-7455
DOI:10.1021/jp411437f