Photoluminescence of n-i-n GaAs/AlAs single quantum well structures under electric field bias

GaAs/AlAs single quantum well structures designed with well thickness near the type I/type-II crossover show distinctive photoluminescence peaks corre sponding to both type-I and type-II recombinations. Photoluminescence measu rements asa function of applied electric field and temperature ranging from 23 to 180 K and current-voltage measurements are presented for two MBE-gro wn structures clad with Si-doped Alq(0.45)Ga(0.55)As layers on n(+)-GaAs [ 100] substrates. The large and field-dependent energy separation between ty pe-I and type-II luminescence peaks is understood to arise from the build-u p of electrons at the X point in the AlAs barrier. (C) 2000 Academic Press.