有效质量差异和电场对GaN/Al_xGa_(1-x)N球形量子点电子结构的影响

Effect of different effective mass and electric field on the electronic structure in GaN/Al_xGa_(1-x)N spherical quantum dot

用平面波展开法对GaN/Al_xGa_(1-x)N球形量子点中类氢杂质态能级随量子点半径、Al组分以及结合能随Al组分的变化规律进行了详细讨论.计算了量子点内外有效质量差异对杂质态能级和结合能的修正,结果表明对于Al组分较高的GaN/Al_xGa_(1-x)N球形量子点,电子有效质量差异对杂质能级和结合能的修正不能忽略.考虑电子有效质量差异后,进一步具体计算了杂质结合能随量子点半径、杂质位置以及外电场的变化规律.

In this paper,we have calculated the impurity electronic states and the binding energy with the variation of the quantum dot radius and Al content in GaN/Al_xGa_ 1-x N spherical quantum dot（QD） using the plane wave method.The modification of the energy states is discussed when the difference in effective electron mass in GaN and Al_xGa_ 1-x N is taken into account.The results show that the difference in effective mass can not be neglected when Al content is large.In addition,with the consideration of the difference in effective mass,we investigate the binding energy as function of quantum dot radius,impurity position and external electric field.The results are meaningful and can be widely applied in the design of optoelectronic devices.