β-Ga_2O_3掺Al的电子结构与能带特性研究

Study on the electronic structures and energy band properties of Al-doped β-Ga_2O_3

采用第一性原理的平面波超软赝势方法,对β-Ga2O3掺Al的AlxGa2-xO3(x=0,0.5,1,1.5,2)合金进行结构优化、电子态密度和能带特性的研究。结果显示,AlxGa2-xO3为间接宽能隙材料,能隙是由导带底Ga 4s态和价带顶O 2p态共同决定,其弯曲系数分别为0.452eV(直接)和0.373eV(间接)。当增大Al的掺杂量,AlxGa2-xO3的体积变小,总能量升高,能隙逐渐增大,这与实验结果相一致。

First-principles plan-wave pseudopotential method was used to calculate the optimized parameters,electron density of states and energy band properties of Ga2-xAlxO3（x=0,0.5,1,1.5,2）alloys by doping Al into β-Ga2O3.It was found that β-Ga2-xAlxO3 was indirect wide-bandgap material,the bowing parameter was 0.452eV for direct bandgap and 0.373eV for indirect bandgap.The bandgap of β-Ga2-xAlxO3 was determined by O2p state of valence band maximum and Ga4 sstate of conduction band minimum.When the increase in Al concentration of Ga2-xAlxO3,the volumes decreased,the total energies and the bandgap increased,which was consistent with the experimental results.