1.3-1.5 μm electroluminescence from Schottky diodes made on Au-InAs/GaAs quantum-size heterostructures

This communication reports the results of experimental studies of the electroluminescence (EL) of forward-biased Schottky barrier (SB) diodes fabricated on heterostructures where an InAs/GaAs quantum dot (QD) layer was placed in the space charge region. In order to reach a higher EL wavelength, the QD layer was overgrown by a thin combined GaAs/InGaAs cladding layer. The heterostructures with Au SBs were found to show pronounced EL originating from several confined exciton states in InAs QDs which is higher at 300 K than at low temperatures. It is shown that the EL wavelength can be tuned within the 1.3-1.57 mum range by changing the thickness and composition of the combined GaAs/InGaAs capping layer. We discuss possible mechanisms of the injection of holes needed for the radiative recombination in the QDs and possibilities of improving the EL quantum yield.