Mutual passivation of electrically active and isovalent impurities in dilute nitrides.
Mutual passivation of electrically active and isovalent impurities in dilute nitrides.
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DOI：
10.1103/physrevlett.100.045505
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发表时间：
2008-01
影响因子：
8.6
通讯作者：
A. Janotti;P. Reunchan;S. Limpijumnong;C. G. Van de Walle
中科院分区：
文献类型：
--
作者：
A. Janotti;P. Reunchan;S. Limpijumnong;C. G. Van de Walle
利用第一性原理计算，我们研究了稀 GaAsN 合金中浅施主 Si 和等价 N 的相互钝化。而不是最近提出的相邻取代位点上的 Si 和 N 配对 (Si(Ga)-N(As)) [K. M. Yu 等人，Nat。马特。 1, 185 (2002); J. Li 等人，物理学。莱特牧师。 96, 035505 (2006)]我们发现N以更显着的方式改变了稀氮化物合金中Si的行为。 N和Si结合成深受主分裂填隙，其中Si和N共享一个As位点[(Si-N)(As)]，其形成能明显低于n型GaAs和稀GaAsN合金中的Si(Ga)-N(As)对。 (Si-N)(As) 的形成解释了 GaAs 带隙恢复以及大约 0.8 eV 处光致发光峰的出现。该模型还可以扩展到Ge掺杂的GaAsN合金，并正确预测在VI列掺杂剂的情况下不存在相互钝化。
Using first-principles calculations we investigate the mutual passivation of shallow donor Si and isovalent N in dilute GaAsN alloys. Instead of the recently proposed pairing of Si and N on adjacent substitutional sites (Si(Ga)-N(As)) [K. M. Yu et al., Nat. Mater. 1, 185 (2002); J. Li et al., Phys. Rev. Lett. 96, 035505 (2006)] we find that N changes the behavior of Si in dilute nitride alloys in a more dramatic way. N and Si combine into a deep-acceptor split interstitial, where Si and N share an As site [(Si-N) (As)], with a significantly lower formation energy than that of the Si(Ga)-N(As) pair in n-type GaAs and dilute GaAsN alloys. The formation of (Si-N)(As) explains the GaAs band-gap recovery and the appearance of a photoluminescence peak at approximately 0.8 eV. This model can also be extended to Ge-doped GaAsN alloys, and correctly predicts the absence of mutual passivation in the case of column-VI dopants.