InGaN量子阱的微观特性

采用VASP程序包模拟计算InGaN量子阱的能带,精细展示了量子阱实空间能带结构。计算结果表明,In原子所在区域出现局域束缚态,导带底与价带顶的简并能级发生分裂,同时量子阱沿垂直结面方向存在分立的能级。此外,针对影响能带的In组分波动、能带弯曲等问题进行探讨,以准确描述其电子行为,从而深入系统地了解InGaN/GaN量子阱的电学光学等特性。

Micro Characteristics of InGaN/GaN Quantum Wells

InGaN/GaN quantum well exhibits a series of unusual optical properties.However,the physics of quantum well on the micro scale is subjected to large uncertainties.Little is known on the discontinuities of energy band structure and local states on the atomic level in the case of different In atoms distribution in the InxGa1-xN layers caused by In compositional fluctuation and phase separation,which intensively alters the optical and electronic pro-perties.Using the efficient and accurate total energy and molecular-dynamics package VASP which is based on the density functional method,we performed the first principles calculations on InGaN/GaN quantum wells.The calcu-lated results exhibit discrete bands around the conduction band minimum and the valence band maximum that vary with the In atom distributions.Moreover,the local states with the discrete bands are likely to appear the quantum confined Stark effect in the InGaN/GaN interface enhanced by the polarization field in the crystal.The control and further understanding of those micro characteristics may lead to the improved performance of InGaN QWs.