Energetics of intrinsic defects in NiO and the consequences for its resistive random access memory performance
Energetics of intrinsic defects in NiO and the consequences for its resistive random access memory performance
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DOI：
10.1063/1.4931751
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发表时间：
2015-09-21
影响因子：
4
通讯作者：
Robertson, J.
中科院分区：
文献类型：
--
作者：
Dawson, J. A.;Guo, Y.;Robertson, J.
杂化密度泛函理论计算。在富氧极限下，Ni空位是差距内所有费米能的最低成本缺陷，与NiO的众所周知的p型行为一致。然而，在电阻式随机存取存储器金属-氧化物-金属设置中的金属电极将氧化学势向贫氧极限移动的能力导致不寻常的NiO行为和在较低费米能级处占主导地位的O空位。计算的能带图显示，在NiO中的O空位在操作费米能量下带正电，从而使其具有不需要清除剂金属层以使漂移最大化的优点。Ni和O的化合物通常被发现是更高的能量比各自的空缺，这表明显着的重组的O空位和化合物不发生所提出的开关行为的一些模型。(C)2015 AIP Publishing LLC.
hybrid density functional theory calculations. At the O-rich limit, Ni vacancies are the lowest cost defect for all Fermi energies within the gap, in agreement with the well-known p-type behaviour of NiO. However, the ability of the metal electrode in a resistive random access memory metal-oxide-metal setup to shift the oxygen chemical potential towards the O-poor limit results in unusual NiO behaviour and O vacancies dominating at lower Fermi energy levels. Calculated band diagrams show that O vacancies in NiO are positively charged at the operating Fermi energy giving it the advantage of not requiring a scavenger metal layer to maximise drift. Ni and O interstitials are generally found to be higher in energy than the respective vacancies suggesting that significant recombination of O vacancies and interstitials does not take place as proposed in some models of switching behaviour. (C) 2015 AIP Publishing LLC.