掺镍镁铝尖晶石电子和光学性质的理论计算  

The Theoretical Calculations on Electronic and Optical Properties of Ni-doped MgAl_2O_4 Spinel

作　　者：李美玲[1] 张悦[1] 

机构地区：[1]鞍山师范学院物理系,辽宁鞍山114007

出　　处：《鞍山师范学院学报》2009年第6期19-22,共4页Journal of Anshan Normal University

摘　　要：采用密度泛函理论的平面波赝势方法(PW-USP)和广义梯度近似(GGA),对替代式0.086%摩尔浓度掺杂的镁铝尖晶石(Ni:MgAl2O4)的电子和光学性质进行了计算.研究结果表明掺镍镁铝尖晶石是具有2.94 eV的窄带隙半导体材料.镍掺杂具有使镁铝尖晶石在费米面附近产生杂质能级,导致光学带隙明显减小的特殊作用.通过分析掺杂晶体的光学性质发现,由于杂质镍的引入,使得可见光及近红外光谱区的吸收明显增强,而这归因于镍3d电子t2g和eg轨道间的d-d跃迁,结果与实验符合较好.The electronic and optical properties of Mg （Ni： MgAl2O4 ） are investigated by use of the density functional theory （DFT）. The calculated results indicate that Mg（ Ni：MgAl2O4 ） is a semiconductor with a small gap 2.94eV. It is concluded that the doping element Ni has specific rule in the MgAl2O4 spinel, which leads it showing dopant energy levels close to the Fermi level and makes the optical gaps smaller than that of MgAl2O4. Due to the Ni-dopant introduction ,the absorption intensity shows an increase in the VIS/NIR range, which is attributed to the d-d transitions between t2g and eg orbitals of Ni3d. Our results are in agreement with the experimental observations.

关 键 词：镍掺杂镁铝尖晶石 密度泛函理论 光吸收 

分 类 号：O643[理学—物理化学]