Donor impurity in InGaN/GaN asymmetric multiple quantum wells

Based on the effective-mass approximation, the binding energy of a donor impurity in zinc-blende (ZB) InGaN/GaN asymmetric multiple quantum wells (AMQWs) is investigated variationally. Numerical results show that the ground-state donor binding energy is highly dependent on the impurity positions and the AMQWs structure parameters. The donor binding energy has a maximum value and the impurity position of the maximum value is localized inside the wide well of the AMQWs. Moreover, the variation of any well width of the AMQWs has a remarkable influence on the donor binding energy. In particular, for the impurity localized inside the wide well, the donor binding energy is insensitive to the increment of the inter-well barrier width when the inter-well barrier width is large. (C) 2010 Elsevier B.V. All rights reserved.