Impact of Four-Valent Doping on the Crystallographic Phase Formation for Ferroelectric HfO2 from First-Principles: Implications for Ferroelectric Memory and Energy-Related Applications
Impact of Four-Valent Doping on the Crystallographic Phase Formation for Ferroelectric HfO2 from First-Principles: Implications for Ferroelectric Memory and Energy-Related Applications
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DOI：
10.1021/acsanm.7b00124
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
C. Kunneth;Robin Materlik;M. Falkowski;A. Kersch
中科院分区：
文献类型：
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作者：
C. Kunneth;Robin Materlik;M. Falkowski;A. Kersch
纳米级掺硅硅氧烷的铁电特性为从铁电存储器到能源相关应用提供了大量的应用前景。这种意外行为的原因尚未得到明确证明，可能包括尺寸效应和兴奋剂效应。采用不同密度泛函理论（DFT）方法，用第一性原理对硅在HfO2中的掺入进行了计算研究。在有氧空位和没有氧空位的HfO2中，间隙硅和取代硅的形成能证明取代缺陷是最可能的。在12.5公式单位%的浓度窗口内，单靠硅掺杂不足以稳定极性和正交晶相（p-o相），这被认为是HfO2中铁电性的来源。另一方面，硅的掺入是p-o相和四方相（t相）最强的促进剂之一。
The ferroelectric properties of nanoscale silicon-doped HfO2 promise a multitude of applications ranging from ferroelectric memory to energy-related applications. The reason for the unexpected behavior has not been clearly proven and presumably includes contributions from size effects and doping effects. Silicon incorporation in HfO2 is investigated computationally by first-principles using different density functional theory (DFT) methods. Formation energies of interstitial and substitutional silicon in HfO2 paired with and without an oxygen vacancy prove the substitutional defect as the most likely. Within the investigated concentration window up to 12.5 formula unit %, silicon doping alone is not sufficient to stabilize the polar and orthorhombic crystal phase (p-o-phase), which has been identified as the source of the ferroelectricity in HfO2. On the other hand, silicon incorporation is one of the strongest promoters of the p-o-phase and the tetragonal phase (t-phase) within the group of investigated ...