A method for evaluating the ground state excitonic band gaps of strained InxGa1-xN/GaN quantum wells

A simple method for calculating the ground state excitonic band gaps of strained wurtzite InxGa1-xN/GaN quantum wells (QWs) for the entire composition range is proposed. The modification of the electronic band structure due to strain becomes significant for high values of indium concentration. It is observed that confinement effects become less important for electrons (due to a shallower well) while the opposite is true for holes (because of a deeper well) in InxGa1-xN/GaN QW with large residual strain. Following the proposed method, one can obtain a satisfactory agreement between the theoretical predictions and experimental observations for ground state excitonic band gaps in InGaN/GaN QWs and InN/GaN ultrathin QWs. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3257263]