Electrical and light-emitting properties of (001)-oriented homoepitaxial diamond p–i–n junction

We have realized high-efficiency excitonic emission with deep-UV light at room temperature for a (001)-oriented diamond p–i–n junction diode consisting of the boron-doped p-type, non-doped intrinsic, and phosphorus-doped n-type layers. High-performance p–i–n junction characteristics were confirmed from current–voltage and capacitance–voltage properties. A strong UV light emission at around 240 nm due to free exciton recombination was observed at a forward current, while the broad visible light emission from deep levels was significantly suppressed compared to that of reported electroluminescence in diamond p–n junctions.