Well-width dependence of the ground level emission of GaN/AlGaN quantum wells

We have performed a systematic investigation of GaN/AlGaN quantum wells gro wn on different buffer layers (either GaN or AlGaN) in order to clarify the role of strain, structural parameters, and built-in field in determining t he well-width dependence of the ground level emission energy. We find that identical quantum wells grown on different buffer layers exhibit strong var iation of the ground level energy but similar well-width dependence. The da ta are quantitatively explained by an analytic model based on the envelope function formalism which accounts for screening and built-in field, and by a full self-consistent tight binding model. (C) 2000 American Institute of Physics. [S0021-8979(00)09105-2].