Electrical and light‐emitting properties of homoepitaxial diamond p–i–n junction

We have investigated the electrical and light‐emitting characteristics of (001)‐oriented homoepitaxial diamond p–i–n junction diodes with the boron‐doped p‐type, non‐doped intrinsic, and phosphorus‐doped n‐type layers formed by applying an optimized homoepitaxial growth technique based on microwave plasma‐enhanced chemical vapor deposition. High‐performance p–i–n junction characteristics were confirmed from current–voltage and capacitance–voltage properties. A strong ultraviolet light emission at around 240 nm due to free exciton recombination was observed at a forward current of over 6 mA, while the broad visible light emission from deep levels was significantly suppressed compared to that of reported electroluminescence in diamond p–n junctions. It was elucidated that the excitonic emission intensity increases superlinearly for the current dependence and is stable even at the high temperature of 200 °C. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)