GREEN LIGHT EMISSIONS FROM GAP-ALXGA1-XP DOUBLE HETEROSTRUCTURES

Green light emissions from GaP-AlxGa1-xP single and double heterostruc tures fabricated by temperature difference method under controlled vap or pressure liquid phase epitaxy, have been studied. When the luminesc ent layer GaP is very thin, we have observed efficient free exciton em issions from GaP-AlxGa1-xP double heterostructures while there is no d etection from homostructures. At least ten times and two times stronge r luminescence efficiencies were obtained from double heterostructures at 77K and loom temperature, respectively. The higher free exciton re combination efficiency is thought to profit from free carrier confinem ent by potential barrier at the interface of GaP and AlxGa1-xP. Also, it is found that shallow impurities enhance the photoluminescence inte nsities in GaP-AlxGa1-xP double heterostructures.