Influence of the additional layer of hexagonal boron nitride (h-BN) on structure, energetics, and electronic spectra of a layer doped with magnesium, silicon, phosphorus, aluminum, or carbon atoms has been examined by theoretical methods. The h-BN layers are modeled as BN clusters of over thirty atoms with the defect in the center. The calculations show that atom positions undergo some modifications in the presence of the second layer, which in several cases lead to significant changes in electronic spectra, like (i) modifications of the character of some states from local excitation to a partial charge transfer; (ii) redshift of the majority of lowest excitations; (iii) absence or appearance of new states in comparison with the monolayers. For instance, a zero-intensity excitation below 4 eV for the carbon atom in place of boron transforms into a dipole-allowed one in the presence of the second layer. A comparison of the interaction energies of doped and undoped clusters shows a strong dependence of the stabilizing of destabilizing effect on the dopant atom, the replaced atom, and in some cases also on the stacking type (AA’ or AB). The stabilization energy per BN pair, calculated for two undoped clusters, is equal to − 31 and − 28 meV for the AA’ and AB stacking, respectively, thus confirming a larger stability of the AA’ stacking for the h-BN case.

中文翻译：

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第二层对掺杂二维六方氮化硼几何形状和光谱特性的影响。


通过理论方法研究了六方氮化硼（h-BN）附加层对掺杂镁、硅、磷、铝或碳原子的层的结构、能量学和电子光谱的影响。 h-BN 层被建模为由 30 多个原子组成的 BN 簇，缺陷位于中心。计算表明，在第二层存在的情况下，原子位置会发生一些变化，这在某些情况下会导致电子光谱发生显着变化，例如（i）某些状态的特征从局部激发到部分电荷转移的变化； (ii) 大多数最低激发的红移； (iii) 与单层相比，新状态的缺失或出现。例如，在第二层存在的情况下，碳原子代替硼的低于 4 eV 的零强度激发会转变为偶极子允许的激发。掺杂和未掺杂团簇的相互作用能的比较表明，不稳定效应的稳定性对掺杂剂原子、被取代的原子以及在某些情况下还对堆叠类型（AA'或AB）有很强的依赖性。对于两个未掺杂簇计算的每个 BN 对的稳定能对于 AA' 和 AB 堆叠分别等于 - 31 和 - 28 meV，从而证实了 h-BN 情况下 AA' 堆叠具有更大的稳定性。