由于自身电子性质的可协调性,镉硫族半导体尤其是掺杂的纳米半导体团簇吸引了广泛关注.采用密度泛函理论的方法对CdnSen (11≤n≤16) 和 Cd15Se16Ag稳定结构进行了模拟研究分析.考虑到Ag原子掺杂在Cd16Se16 纳米团簇中位置的不同,主要讨论了两种可能的掺杂位(S1, S2).基于此,详细地分析了Cd15Se16AgS1 和 Cd15Se16AgS2团簇的几何结构和电子性质.Ag原子的掺杂改变了其自身的对称群和大小,而Ag原子掺杂位置的不同也被重点关注.此外,详细分析了结合能、带隙、态密度和电荷密度分布.结果表明掺杂后引入了一个新的能级,该能级被称为受主能级.介于价带和导带间的受主能级电荷密度的贡献主要来自于Se原子的p轨道和Ag原子的d轨道.这些说明了Ag原子掺杂和掺杂位置是两个影响着团簇电子性质的重要原因.%Cadmium chalcogenide semiconductor, especially doped nanoclusters, have attracted so much concern for their tunability of its electronic properties.The ultra-stable CdnSen (11≤n≤16) and Cd15Se16Ag structures were investigated by density functional theory.Considering the effect of doping site in Ag-doped Cd16Se16 nanocluster, two possible substitutional sites (S1, S2) were discussed.Based on it, the structural and electrical properties of Cd15Se16AgS1 and Cd15Se16AgS2 were studied in detail.Indeed, the Ag atom doping affected its original symmetry group and size.Particular attention was paid to the effects of Ag substitutional sites.Furthermore, the bingdingenergy, energy gap, density of states and charge density distributions were analyzed, revealing that one new energy level called acceptor level was introduced in the original system.The charge distribution of acceptor level which was between valence band and conduction band, mainly from p-orbital of Se atoms and d-orbital of Ag atom.These illustrate that metal (Ag atom) doping and substitutional sites are two important factors for its electrical properties.
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