PIEZOELECTRIC EFFECT ON OPTICAL-PROPERTIES OF PSEUDOMORPHICALLY STRAINED WURTZITE GAN QUANTUM-WELLS

The presence of internal strain in wurtzite quantum-well (QW) structur es may lead to the generation of large polarization fields. These piez oelectric fields cause a spatial separation of the electrons and holes inside the QW to screen the internal fields. A self-consistent calcul ation of optical gain and the corresponding differential gain is prese nted in pseudomorphically strained GaN quantum wells as a function of carrier density. Based on the local exchange-correlation potential, el ectron and hole band structures are obtained by coupling Poisson's equ ation with an effective-mass Schrodinger equation in the conduction ba nd and an envelope-function (or k . p) Hamiltonian in the valence band , Our calculations show that self-consistent calculations including th e piezoelectric effects are essential for accurate description of stra ined wurtzite QW structures.