Chemical Trends of Surface Reconstruction and Band Positions of Nonmetallic Perovskite Oxides from First Principles
Chemical Trends of Surface Reconstruction and Band Positions of Nonmetallic Perovskite Oxides from First Principles
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DOI：
10.1021/acs.chemmater.2c03615
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发表时间：
2023-02
影响因子：
8.6
通讯作者：
Yasuhide Mochizuki;Ha-Jun Sung;Tomoya Gake;F. Oba
中科院分区：
文献类型：
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作者：
Yasuhide Mochizuki;Ha-Jun Sung;Tomoya Gake;F. Oba
结合第一性原理计算的进化算法搜索进行系统地预测重构的非金属钙钛矿氧化物的表面结构。在NaTaO_3，KTaO_3，CaTiO_3，SrTiO_3，YAlO_3和LaAlO_3的宏观化学计量比（001）表面上，分别得到了A + B_5 + O_3，A_2 + B_4 + O_3和A_3 + B_3 + O_3体系的四种最低能量重构模式。我们解释的表面能和能带位置的10个钙钛矿氧化物的化学趋势，另外包括KNbO 3，BaTiO 3，BaZrO 3，和LaGaO 3，在最外层重建的表面层的原子环境。在表面上重新获得A-O（B-O）配位数和键长可以稳定A2 +B4+ O3和A3 +B3+O3（A+B5+O3）表面。降低阳离子A（B）的配位数导致相对于真空能级的浅（深）价带最大值和导带最小值。我们的研究为非金属钙钛矿氧化物的表面重构和能带排列提供了一般性的见解。
An evolutionary algorithm search in combination with first-principles calculations is performed to systematically predict the reconstructed surface structures of nonmetallic perovskite oxides. Four types of lowest-energy reconstruction patterns are obtained for the macroscopically stoichiometric (001) surfaces of NaTaO3, KTaO3, CaTiO3, SrTiO3, YAlO3, and LaAlO3as representatives ofA+B5+O3,A2+B4+O3, andA3+B3+O3systems. We explain chemical trends in the surface energies and band positions of 10 perovskite oxides, additionally including KNbO3, BaTiO3, BaZrO3, and LaGaO3, in terms of the atomic environments at the outermost reconstructed surface layers. RegainingA–O (B–O) coordination numbers and bond lengths at the surfaces is found to stabilize theA2+B4+O3andA3+B3+O3(A+B5+O3) surfaces. Decreasing the coordination number of cationA(B) leads to shallow (deep) valence band maxima and conduction band minima relative to the vacuum level. Our study provides general insights into the surface reconstruction and band alignment of nonmetallic perovskite oxides.