钎锌矿相GaN电子高场输运特性的Monte Carlo模拟研究  

Electron transport property in wurtzite GaN at high electric field with Monte Carlo simulation

作　　者：郭宝增[1] 张锁良[1] 刘鑫[1] 

机构地区：[1]河北大学电子信息工程学院

出　　处：《物理学报》2011年第6期806-811,共6页Acta Physica Sinica

基　　金：河北省自然科学基金(批准号:F2009000226);河北省教育厅科学研究计划(批准号:2008308)资助的课题~~

摘　　要：应用全带多粒子Monte Carlo模拟方法,研究了钎锌矿相GaN材料电子的高场输运特性.模拟中利用了基于第一性原理总能量赝势方法计算得到的纤锌矿GaN的能带结构数据.用Cartier的方法,计算碰撞电离散射率.计算得到了电子平均漂移速度和电子平均能量与电场的关系曲线.电离系数的分析表明当电场强度大于1MV/cm时,才会有明显的碰撞电离发生,量子产额的分析表明当电子的能量大于7eV时,量子产额随能量增加迅速增大.研究了在0—4MV/cm电场强度范围内电子在各导带的分布,低场下电子全部位于第1导带,随着电场增加电子跃迁到更高的导带上.在所研究的电场范围内,电子主要位于第1和第2导带,高场下一些电子位于第3、第4和第5导带,第7和第8导带上的电子极少.We present the results of the electron transport property in wurtize GaN using an ensemble full band Monte Carlo simulation.The data of wurtzite GaN band structure calculated with the first-principles total-energy pseudopotential method is used in the simulations.The impact ionization scattering rate is calculated based on Cartier＇s method.The average electron drift velocity and the average electron energy each as a function of electric field are computed.The electron impact ionization coefficient is calculated as a function of applied electric field.The analysis of the impact ionization coefficient shows that when the applied electric field is greater than 1 MV/cm,the obvious impact ionization events occur.The analysis of the quantum yield shows that when the electron energy is greater than 7 eV,the quantum yield increases rapidly with electron energy increasing.We study the occupancy of the electrons in the eight conduction bands at the applied electric field ranging from 0 to 4 MV /cm.For the case of the low applied electric field all of the electrons are located in the 1st conduction band.With the increase of the applied electric field,some of the electrons move to high index conduction bands.For the whole range of the applied electric field,most of the electrons are located in the 1st conduction band and 2nd conduction band,a small number of the electrons are located in the 3rd,4th and 5th conduction band,and very few electrons are located in the 7th and 8th conduction band.

关 键 词：碰撞电离 高场输运 能带结构 MONTE CARLO模拟 

分 类 号：O481[理学—固体物理]