Electrically driven single-photon source at room temperature in diamond

Single-photon sources that provide non-classical light states on demand have a broad range of applications in quantum communication, quantum computing and metrology(1). Single-photon emission has been demonstrated using single atoms(2), ions(3), molecules(4), diamond colour centres(5,6) and semiconductor quantum dots(7-11). Significant progress in highly efficient(8,11) and entangled photons(9) sources has recently been shown in semiconductor quantum dots; however, the requirement of cryogenic temperatures due to the necessity to confine carriers is a major obstacle. Here, we show the realization of a stable, room-temperature, electrically driven single-photon source based on a single neutral nitrogen-vacancy centre in a novel diamond diode structure. Remarkably, the generation of electroluminescence follows kinetics fundamentally different from that of photoluminescence with intra-bandgap excitation. This suggests electroluminescence is generated by electron-hole recombination at the defect. Our results prove that functional single defects can be integrated into electronic control structures, which is a crucial step towards elaborate quantum information devices.