Donor bound excitons confined in a GaN/Ga1-xAlxN quantum dot

Exciton states confined in a GaN/Ga1-xAlxN Quantum dot are investigated within the framework of single band effective mass approximation. Charged donor bound exciton, D+X energy is computed as a function of dot radius for different Al concentration and the height of cylindrical dot. The interband optical transition of GaN/Ga1-xAlxN dot is calculated with the various structural parameters. The valence band anisotropy is included in our theoretical model by using different hole masses in different spatial directions Binding energy of the ground state of exciton is calculated, with the inclusion of 2D Hartree dielectric screening function Our results show that quantum size has a considerable influence on exciton states and interband optical transitions of the narrow dots. The ground state exciton binding energy and the interband emission energy are increased when the cylindrical quantum dot height or radius is decreased and the effect of exciton has influence on the interband emission energy. The donor bound exciton binding energy increases monotonically as Al concentration increases. Our results are compared with the existing available literature. (C) 2010 Elsevier Ltd All rights reserved