Near‐Unity External Quantum Efficiency in GaAs|AlGaAs Heterostructures Grown by Molecular Beam Epitaxy

Abstract

The external quantum efficiency (EQE) of a GaAs|AlGaAs double heterostructure, grown by molecular beam epitaxy, is measured as a function of temperature in the range of 350–100 K. Record EQEs of >80% at 300 K and >98% below 150 K are obtained. The temperature‐dependent lifetime measurement that corroborates the EQE data is also reported, suggesting that interface recombination remains the dominant mechanism for nonradiative decay. These results offer promising prospects for using these structures in thermal photovoltaic, electroluminescent, and laser cooling device applications.