Graded interface effects on the carriers confinement in single GaN/AlxGa1-xN wurtzite quantum wells

In this article, we present a theoretical study of graded interface effects on the carriers (electron and heavy-hole) confinement properties in single GaN/AlxGa1-xN quantum wells. The smooth interfaces are described assuming error function-like patterns for the interfacial aluminum molar fraction va riations, from which the carriers confinement potential and effective masse s are obtained. We show the occurrence of graded interface-related blue shi fts on the carriers confinement energies and intersubband transitions, whos e strength depends on the GaN/AlxGa1-xN quantum well and graded interface w idths. The highest intersubband transitions, which can occur within the com monly used square quantum well picture, are eliminated when the existence o f smooth interfaces is taken into account. (C) 1999 Elsevier Science Ltd. A ll rights reserved.