Dong Xiao, Wang Tianxing, An Yipeng, Wang Yongyong
School of Physics, Henan Normal University, 453007 Xinxiang, People's Republic of China.
J Phys Condens Matter. 2021 Mar 17;33(11):115502. doi: 10.1088/1361-648X/abd524.
A hyperdoped diamond material is engineered by first-principles calculations in this work. Several deep-level elements, such as S, Se, Te, Co, Au, V, Ni, are chosen as dopants in the diamond. The formation energy results show that the substitutional configuration of the dopants is more stable than the interstitial ones. The substitutional configurations of chalcogen dopants (S, Se, Te) can introduce a nearly filled intermediate band (IB) in the upper half of the bandgap of the diamond. The substitutional configurations of several transition metals, such as Co, Au, V, Ni, and Cu, can form partially filled IB(s) near the center of the bandgap, which is more appropriate than that formed by the chalcogens. The dielectric function results indicate that all of these deep-level elements can lead to the sub-bandgap absorption and the absorption range and intensity vary dramatically with different dopants. Among these dopants, Co, Au, and Cu exhibit a special strong sub-bandgap absorption in a longer wavelength range, which would make the material to be an excellent photoelectric device. With reducing the concentration of the transition metal dopants, the IBs in the bandgap are narrower and tend to separate from each other and the sub-bandgap absorptions reduce sharply. Our conclusions imply that the photoelectric properties of the novel diamond material would be modulated by changing the dopant types and concentrations.
在这项工作中,通过第一性原理计算设计了一种超掺杂金刚石材料。选择了几种深能级元素,如S、Se、Te、Co、Au、V、Ni作为金刚石中的掺杂剂。形成能结果表明,掺杂剂的替代构型比间隙构型更稳定。硫族元素掺杂剂(S、Se、Te)的替代构型可以在金刚石带隙的上半部分引入一个近满的中间带(IB)。几种过渡金属,如Co、Au、V、Ni和Cu的替代构型可以在带隙中心附近形成部分填充的中间带,这比硫族元素形成的中间带更合适。介电函数结果表明,所有这些深能级元素都会导致带隙以下吸收,并且吸收范围和强度随不同的掺杂剂而显著变化。在这些掺杂剂中,Co、Au和Cu在更长的波长范围内表现出特殊的强带隙以下吸收,这将使该材料成为一种优异的光电器件。随着过渡金属掺杂剂浓度的降低,带隙中的中间带变窄并趋于相互分离,带隙以下吸收急剧减少。我们的结论表明,新型金刚石材料的光电性能可以通过改变掺杂剂类型和浓度来调节。