Mechanism of photoconductivity gain for p-diamond Schottky photodiode

Persistent photocurrent and photoconductivity gains are observed for WC Schottky photodiodes fabricated on boron-doped p-diamond homoepitaxial layers. The decay time and the gain are sensitive to the boron doping, and increasing the boron concentration increases the decay time and the gain simultaneously. The mechanism of the persistent photoconductivity and the gain is explained by existence of an electron trap with low emission and recombination rate. It is essential to control the boron concentration for developing highly-sensitive diamond photodiode with fast response speed.