Mid-infrared electroluminescence from type-II In(Ga)Sb quantum dots

Abstract

There exists significant interest in the demonstration and development of alternative mid-infrared emitters, with future applications for thermal scene projection, low-cost infrared sensing, and possible long-wavelength quantum communication applications. Type-II In(Ga)Sb quantum dots grown in InAs matrices have the potential to serve as a viable material system for wavelength-flexible, mid-infrared sources. Here, we dramatically expand the range of potential applications of these mid-infrared quantum emitters through the demonstration of surface-emitting electrically pumped mid-infrared light-emitting diodes with active regions utilizing type-II In(Ga)Sb quantum dots. Two device structures were studied, the first iteration being a single In(Ga)Sb insertion layer within a simple PIN structure and the second being a design engineered for improved room temperature emission with the addition of lattice matched AlAsSb cladding at the anode to block electrons and five layers of In(Ga)Sb dots to increase the effective volume of active material. Samples were grown by molecular beam epitaxy and the electrical and optical properties for each design were characterized as a function of temperature.