过渡金属Cd掺杂4H-SiC的磁性和光学性能研究

Study on Magnetic and Optical Properties of Transition Metal Cd-doped 4H-SiC

基于第一性原理密度泛函理论(DFT)的广义梯度近似(GGA)的平面波赝势法(PBE),计算了4H-SiC的本征体系、过渡金属元素Cd单掺杂4H-SiC体系的电子结构、磁性和光学特性。结果表明,在掺杂浓度为1.359×10^(21)cm^(-3)情况下,产生了0.6μB的磁矩,Cd掺杂均为p型掺杂,掺杂后体系仍为间接带隙材料,但是禁带宽度减小为1.27 eV,这表明它们可以作为自旋电子元器件的备选材料。Cd掺杂体系的静态介电常数在垂直c轴和平行c轴方向分别为19.741和5.303.在垂直c轴方向出现双介电耗损峰,在平行c轴方向出现单介电耗损峰。

The electronic structure,magnetic and optical properties of the intrinsic,Cd doped of 4H-SiC system have been investigated using density functional theory,which is based on first principles generalized gradient approximation(GGA)plane wave and plane wave pseudo-potential method(PBE).The calculation indicates that when the doping concentration of Cd is 1.359×10^(21)cm^(-3),the doping system can generate magnetic moment of 0.6μB.The system of 4H-SiC doped with Cd is an indirect p type semiconductor with the band gap of 1.27 eV.The caculation indicates that the dopping system of Cd can be used as alternative material for Spintronic Devices.The static permittivity of the Cd doped system is 19.741 and 5.303 in the vertical c axis and the parallel c axis directions,respectively.The Cd doped system has a double dielectric loss peak in the vertical c axis and a single dielectric loss peak in the parallel c axis.