Built-In Electric Fields and Electronic Structure of GaN/AlN QDs

Abstract : We present a theory of the electronic structure of GaN/AIN QDs including built-in strain and electric field effects. A simple analytical formula is derived for the Fourier transform of the built-in electrostatic potential. The QD carrier spectra and wave functions are calculated using an original method we have developed based on an 8-band k.P model. It is shown that due to the strong built-in electric field, the holes are localized in the wetting layer just below the QD bottom, while electrons are pushed up to the pyramid top. The energy of the ground optical transition is found to be in good agreement with available experimental data.