Abstract
A light emitting diode with superconducting Nb electrodes was fabricated to investigate the contribution of cooper pairs to radiative recombination in a semiconductor. Electroluminescence observed from the active layer in which electron cooper pairs and normal holes are injected was drastically enhanced at the temperature lower than the superconducting transition temperature of the Nb electrodes. This is the first experimental evidence that cooper pairs enhance radiative recombinations by the superradiance effect.