Strain-Engineered Formation, Migration, and Electronic Properties of Polaronic Defects in CeO2
Strain-Engineered Formation, Migration, and Electronic Properties of Polaronic Defects in CeO2
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CeO2 中极化子缺陷的应变工程形成、迁移和电子特性
DOI：
10.1002/pssb.202100020
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Zhou Miao
中科院分区：
文献类型：
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作者：
Zhang Ling;Sun Lu;Meng Qingling;Wu Jinge;Hao Xiamin;Zhai Shuwei;Dou Wenzhen;Jia Yizhen;Zhou Miao
报告了二氧化铈（CeO2）中极化子缺陷的应变工程形成、电子结构和迁移特性的第一性原理研究，包括单极化子、氧空位（Vo2+）和极化子-空位复合物[（Vo2+–1极化子）1+，（Vo2+–2极化子）0]。结果表明，氧空位的形成能随着拉伸和压缩双轴应变的增加而增加，而极化子和极化子-空位复合物的形成能随着拉伸（压缩）应变的减少（增加），因此它们的缺陷浓度随应变和温度的变化而表现出极大的不同。有趣的是，由于不同的变形势，极化缺陷态可以随着应变向带边缘移动，有利于增强电导率。进一步探讨了CeO2中极化子的迁移，揭示了应变诱导的定向迁移的趋势。这些发现不仅揭示了 CeO2 中极化子缺陷的基本性质，而且还为基于氧化物的功能微电子、电池和催化剂提供了一种将缺陷工程与应变工程相结合的有吸引力的方法。
First‐principles investigations on the strain‐engineered formation, electronic structures, and migration properties of polaronic defects in ceria (CeO2), including single polarons, oxygen vacancies (Vo2+), and polaron–vacancy complexes [(Vo2+–1polaron)1+, (Vo2+–2polaron)0], are reported. Results show that the formation energy of oxygen vacancy increases with both tensile and compressive biaxial strain, whereas the formation energies of polarons and polaron–vacancy complexes reduce (increase) with tensile (compressive) strain, so that their defect concentrations behave drastically different with strain and temperature. Interestingly, due to the distinct deformation potentials, the polaronic defect states can shift toward band edges with strain, beneficial for enhanced electrical conductivity. The migration of polarons in CeO2is further explored, and a tendency of strain‐induced directional migration is revealed. These findings not only shed light on the fundamental properties of polaronic defects in CeO2but also provide an attractive approach of combining defect engineering with strain engineering for oxide‐based functional microelectronics, batteries, and catalysts.