First-principles study of native defects and lanthanum impurities in NaTaO3
First-principles study of native defects and lanthanum impurities in NaTaO3
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DOI：
10.1103/physrevb.78.014115
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发表时间：
2008-07
影响因子：
3.7
通讯作者：
Minseok Choi;F. Oba;I. Tanaka
中科院分区：
文献类型：
--
作者：
Minseok Choi;F. Oba;I. Tanaka
采用基于密度泛函理论的第一性原理计算方法研究了${\text{NaTaO}}_{3}$中晶格空位、反位缺陷和镧杂质的形成能和电子结构. Na反位和Ta空位，这两者都是多个受体，在富O条件下是能量有利的，而O空位，这是一个双施主，在O-贫条件下是优选的。的Ta反位是一个四重供体，但其高的形成能使它不太可能是稳定的热平衡下比$p$型和O-贫条件。在La掺杂的${\text{NaTaO}}_{3}$中，在贫氧条件下，Na位的替代La可能形成双施主。预计将产生载流子电子，除了重掺杂的情况下，在Ta的网站，以及原生受体，由受体样的La补偿是显着的。对于所有的原生缺陷和La杂质，没有本地化的单电子态被发现在带隙中，这是一致的浅施主/受主行为确定使用的形成能。
The formation energies and electronic structure of lattice vacancies, antisite defects, and lanthanum impurities in ${\text{NaTaO}}_{3}$ are investigated using first-principles calculations based on density-functional theory. The Na antisite and the Ta vacancy, which are both multiple acceptors, are energetically favorable under O-rich conditions, whereas the O vacancy, which is a double donor, is preferred under O-poor conditions. The Ta antisite is a quadruple donor but its high formation energy renders it unlikely to be stable under the thermal equilibrium other than $p$-type and O-poor conditions. In La-doped ${\text{NaTaO}}_{3}$, substitutional La at the Na site is likely to form as a double donor under O-poor conditions. It is expected to generate carrier electrons except for heavily doped cases where compensation by acceptorlike La at the Ta site, as well as the native acceptors, is significant. For all the native defects and La impurities, no localized one-electron states are found in the band gap, which is consistent with the shallow donor/acceptor behavior determined using the formation energies.