B,N协同掺杂金刚石电子结构和光学性质的第一性原理研究

基于金刚石的稳定结构, 在实验研究的基础上, 本文采用基于周期性密度泛函理论计算了B/N单掺杂、共掺杂金刚石的晶体结构, 并就掺杂方式和掺杂后形成能进行了对比研究, 得到了B/N双掺杂的最稳定结构. 在此基础上, 进一步计算了N单掺杂及B/N共掺杂最稳定结构的吸收光谱、电子结构和态密度. 通过与实验结果对比可以看出, 较N单掺杂, B/N共掺杂的吸收光谱发生明显红移, 与实验符合较好. 计算结果表明: N原子单掺杂优先于B原子; 由于原子间的协同作用, B/N近邻共掺杂体系的形成能最低, 为掺杂的最可能结构.

First-principle studies of the electronic structures and optical properties of diamond crystal co-doped with B and N

On the basis of our previous experimental results for the diamond synthesized in FeNi-C system by B and N co-doping under high pressure and high temperature conditions, the crystals doped with B or N atom, and co-doped with B and N atom are investigated separately by using the first principle density functional theory based on the stable structure of diamond. The formation energies corresponding to the all doping diamond crystals are studied while the most stable co-doping structures with the lowest energy are obtained. Furthermore, the absorption spectra, the densities of states, and the electronic structures of the doping diamond crystals are discussed. The absorption spectra show obviously the red shift, which is consistent with the experimental result. The electronic results show that the doping of N atom is prior to the doping of B atom while the system co-doped with nearly neighboring B and N atoms creates the most stable structure with the lowest formation energy due to the synergistic effect.