Ultrahigh spontaneous emission quantum efficiency, 99.7% internally and 72% externally, from AlGaAs/GaAs/AlGaAs double heterostructures

Optically thin AlGaAs/GaAs/AlGaAs double heterostructures, (5000 Å), are floated off their substrates by the epitaxial liftoff technique and mounted on various high reflectivity surfaces. From the absolute photoluminescence intensity, we measure internal and external quantum efficiencies of 99.7% and 72%, respectively. High spontaneous emission quantum efficiency, is important for photon number squeezed light, diode lasers, single-mode light-emitting-diodes, optical interconnects, and solar cells.