GaAs/Ga_(1-x)Al_xAs量子阱结构能带的不连续性

Band Offset of GaAs/Ga_(1-x)Al_xAs Quanlun) Well Structures

用改进的方势阱模型、半导体统计方法,研究了决定GaAs/Ga_(1-x)Al_xAS量子阱结构中能带不连续的参数Qe与热平衡费米能级的关系,Qe作为一个统计参数,不仅与组分x、阱宽L有关,还与温度有关,计算表明,对不同的x、L值,Qe的数值可在一个相当大的范围内变化,在同样组分下,阱宽越大,Qe越小;在同样阱宽下,组分越高,Qe越小,计算结果与一些实验结果符合得很好。

By using a modified square well model, and with the help of semiconductor statistics, the relationship between the band offset' parameter Qe and thermal-equalibrium Fermi-level in GaAs/Ga1-xAlxAs quantum well structures have been investigated. As a statistic parameter, Qe is not only composition and well width dependent, but also temperature dependent. Our calculation demonstrated that Qe may change in a rather wide range. while varying x and L.For a fixed composition, the larger the well width, the smaller the Qe, for a fixed well vidth,the higher the composition,the smaller the Qe. The calculated results agree well with certain experimental rosuits.