Optically detected magnetic resonance study of the transition from pseudodirect type-II to type-I GaAs/AlAs superlattices

Abstract Optically detected magnetic resonance and level anticrossing spectroscopy have been applied for the first time for a study of GaAs/AlAs superlattices (SL) in the transistion region type-II SL (Γ hole in the GaAs layer and X electron in the AlAs layer)—type I SL (Γ hole and Γ electron both in the GaAs layer). Three kinds of heavy-hole excitons which are typical for type-II SL, for the transition type-II/type-I and for type-I SL with the lifetime down to 300 ps have been evidenced in the transition region and their g -factors and exchange splitting parameters have been measured.