Optical properties of III nitrides grown by reactive MBE

Properties of GaN and GaN/AlGaN structures deposited by reactive MBE where the reactive nitrogen source is provided by thermal disassociation of ammonia on the substrate surface. Bulk GaN layers with excellent excitonic transitions on sapphire, GaN buffer layers deposited by MOCVD, and ZnO substrates have been obtained. So have the GaN/AlGaN separate confinement heterostructures exhibiting optical pumping threshold powers of under 90 kW/cm/sup 2/ diode along with DH AlGaN/GaN LEDs. Recently, pin diode UV detectors exhibiting what appears to be excitonic response at room temperature with a sensitivity of about 0.1 A/W near the band edge have been obtained.