Suppression of Metal-Insulator Transition in VO2 by Electric Field-Induced Oxygen Vacancy Formation
Suppression of Metal-Insulator Transition in VO2 by Electric Field-Induced Oxygen Vacancy Formation
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DOI：
10.1126/science.1230512
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发表时间：
2013-03-22
期刊：
影响因子：
56.9
通讯作者：
Parkin, Stuart S. P.
中科院分区：
文献类型：
--
作者：
Jeong, Jaewoo;Aetukuri, Nagaphani;Parkin, Stuart S. P.
离子液体电解质门控是在相关绝缘体中诱导新导电相的有力工具。一种典型的相关材料是二氧化钒（VO 2），它仅在低于特征相变温度的温度下绝缘。我们表明，电解质门控的外延薄膜的VO 2抑制金属-绝缘体的过渡和稳定的金属相的温度低于5开尔文，即使在离子液体被完全删除。我们发现，VO 2的电解质门控导致静电诱导的载流子，而是电场诱导的氧空位的产生，随之而来的氧从氧化物膜迁移到离子液体。在解释离子液体门控实验时应考虑这一机制。
Electrolyte gating with ionic liquids is a powerful tool for inducing novel conducting phases in correlated insulators. An archetypal correlated material is vanadium dioxide (VO2), which is insulating only at temperatures below a characteristic phase transition temperature. We show that electrolyte gating of epitaxial thin films of VO2 suppresses the metal-to-insulator transition and stabilizes the metallic phase to temperatures below 5 kelvin, even after the ionic liquid is completely removed. We found that electrolyte gating of VO2 leads not to electrostatically induced carriers but instead to the electric field-induced creation of oxygen vacancies, with consequent migration of oxygen from the oxide film into the ionic liquid. This mechanism should be taken into account in the interpretation of ionic liquid gating experiments.