Band gap renormalization and observation of the type I–type II transition in quantum well systems

Quantum wells (or barriers) are of finite extent (≤100 Å) along the growth direction. Hence, for at least one or two monolayers adjacent to the interface, the corresponding one-electron potential in the conduction (or valence) band must differ from that appropriate to the bulk material. The present article demonstrates the pronounced effect such short-range ‘‘interface potentials’’ can have on the transition energies and oscillator strengths in a dilute magnetic semiconductor system undergoing a type I–type II transition in an external magnetic field.