Electroluminescence investigation of GaAs/AlAs monolayer multiquantum well structures

We present experimental studies of electroluminescence in GaAs/AlAs type II monolayer multiquantum well (MQW) heterostructures embedded in InAlP undoped confinement layer grown by low pressure MOVPE. The p-n junction in structure was created by local diffusion of Zn from conductive ZnO film. The phonon assisted optical processes are observed at room temperature where indirect optical transitions at 545 and 720 nm are present in weak electroluminescence spectra. Intense optical transition at 572 nm prevail at the low temperature (77 K) which corresponds to type I optical transition. Type II optical transition at 688 nm in GaAs/AlAs MQW structure shows low intensity. The electroluminescence of type I optical transitions in type II monolayer GaAs/AlAs MQW structures is reported for the first time.