第一性原理下铟锰共掺铌酸锂晶体的电子结构和吸收光谱

发布时间：2019-02-15 14:55

【摘要】：本文利用第一性原理研究了In:Mn:LiNbO_3晶体及对比组的电子结构和光学特性.研究结果显示,掺锰铌酸锂晶体的杂质能级主要由Mn的3d态轨道贡献,在禁带中处于较浅的位置,在价带顶端也有所贡献,晶体带隙较纯铌酸锂晶体变窄;Mn:LiNbO_3晶体分别在1.66,2.85 eV等位置形成了吸收峰;掺In的Mn:LiNbO_3晶体在1.66 eV附近的吸收明显减弱,掺铟浓度约为闽值(约3 mol%)时在1.66 eV吸收继续减弱,并出现了一些新的光吸收峰.本文提出了1.66 eV的吸收与Mn2+离子相关,因掺铟离子而出现的2.13 eV的吸收与Mn~(3+)离子相关,这两峰随着掺铟离子的增加将出现前者减弱而后者增强的变化,该变化可以用电荷在锰、铟离子间的转移解释;还提出在铟、锰共掺铌酸锂晶体中,若光存储的记录光选择低能段(1.66 eV附近),此时对应记录灵敏度要求较小的掺铟量等观点.
[Abstract]:In this paper, the electronic structure and optical properties of In:Mn:LiNbO_3 crystal and its contrast group have been studied by first principle. The results show that the impurity energy levels of Mn-doped lithium niobate crystals are mainly contributed by the 3D state orbital of Mn, which are in a shallow position in the gap and at the top of the valence band. The band gap of the crystal becomes narrower than that of the pure lithium niobate crystal. The absorption peaks of Mn:LiNbO_3 crystals were formed at the same position of 1.66U 2.85 eV. The absorption of Mn:LiNbO_3 crystal doped with In decreases obviously near 1. 66 eV, and the absorption of Mn:LiNbO_3 doped with indium continues to weaken at 1. 66 eV when the concentration of indium is about 3 mol%, and some new absorption peaks appear. In this paper, we propose that the absorption of 1. 66 eV is related to Mn2 ion, and that the absorption of 2. 13 eV due to indium ion is related to Mn~ (3) ion. The former weakens and the latter increases with the increase of indium ion. This change can be explained by the transfer of charge between manganese and indium ions. It is also proposed that in indium and manganese co-doped lithium niobate crystals, the recording light stored by the light can be stored in a low energy band (near 1. 66 eV), which corresponds to a lower recording sensitivity.
【作者单位】：西南大学物理科学与技术学院;
【基金】：国家自然科学基金(批准号:11274257)资助的课题~~
【分类号】：O73

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