Room Temperature Upconversion Electroluminescence From A Mid-Infrared In(Asn) Tunneling Diode

Light emitting diodes (LEDs) in the mid-infrared (MIR) spectral range require material systems with tailored optical absorption and emission at wavelengths lambda > 2 mu m. Here, we report on MIR LEDs based on In(AsN)/(InAl)As resonant tunneling diodes (RTDs). The N-atoms lead to the formation of localized deep levels in the In(AsN) quantum well (QW) layer of the RTD. This has two main effects on the electroluminescence (EL) emission. By electrical injection of carriers into the N-related levels, EL emission is achieved at wavelengths significantly larger than for the QW emission (lambda similar to 3 mu m), extending the output of the diode to lambda similar to 5 mu m. Furthermore, for applied voltages well below the flatband condition of the diode, EL emission is observed at energies much larger than those supplied by the applied voltage and/or thermal energy, with an energy gain Delta E>0.2eV at room temperature. We attribute this upconversion luminescence to an Auger-like recombination process.