纤锌矿相GaN空穴输运特性的Monte Carlo模拟研究

用全带多粒子Monte Carlo方法模拟纤锌矿相(Wurtzite)GaN空穴输运特性的结果. 用经验赝势法计算得到能带结构数据. 模拟包含了声学声子散射，光学声子散射，极性光学声子散射，压电散射，电离杂质散射及带间散射等散射机理. 计算得到了空穴沿3个主要对称方向上的空穴平均漂移速度和平均能量与电场强度的关系曲线，室温下漂移速度呈现饱和特性. 在所研究的电场范围内，最大平均漂移速度约为6×10⁶cm s^-1，最大空穴平均能量约为0.12eV, 这些值均比电子的相应参数低很多. 还给出了空穴的扩散迁移率与杂质浓度关系的模拟结果. 关键词： 蒙特卡罗 氮化镓 输运特性 能带结构

Monte Carlo simulation of the hole transport properties for wurtzite GaN

The simulation of the hole transport properties of wurtzite phase GaN are performed by the full band ensemble Monte Carlo approach. The band structure data of GaN used in the simulation are obtained by the empirical pseudopotential method. The scattering mechanisms included in the simulation are acoustic phonon scattering, optical phonon scattering, polar optical phonon scattering, piezoelectronic scattering, ionized impurity scattering, as well as the intervalley scattering. The dependence of the hole average drift velocity and average energy in three main symmetry directions for wurtzite GaN on the electric field are obtained. At room temperature, the velocity-field relation shows the non-saturated characteristics. The maximum drift velocity is about 6×10⁶ cm s^-1, and the maximum average energy is 0.12 eV in the range of the field of this work. These values are much smaller than the corresponding parameters of the electrons in GaN. Furthermore, the dependence of the diffusion mobility on the impurity density is reported.