Luminescence of n-InGaAs/p-InP light emitting diode with superconducting Nb electrode

To demonstrate the contribution of Cooper pairs to radiative recombination in a semiconductor, a n-InGaAs/p-InP light emitting diode with superconducting Nb electrodes was fabricated. Electroluminescence as well as photoluminescence from the n-InGaAs into which electron Cooper pairs were expected to penetrate from the superconducting Nb electrodes by the proximity effect was drastically enhanced at the temperature lower than the superconducting transition temperature. This is the experimental evidence that Cooper pairs enhance radiative recombinations by the superradiance effect.