Fabrication and Characterization of (100)-Oriented Single-Crystal Diamond p–i–n Junction Ultraviolet Detector

A (001)-oriented single-crystal diamond p–i–n junction ultraviolet (UV) detector is fabricated and its optoelectronic properties are investigated. The detector exhibits a clear rectifying I–V characteristic with a rectification ratio of 223 at ±5 V. At a reverse bias of 5 V, the responsivity is 1.69 A W⁻¹ under an irradiation of 210 nm light, and the 210 nm/400 nm UV-to-visible rejection ratio reaches 10³. The time response characteristic shows a long rise time and decay time, which are mainly caused by the carrier trapping in the n-type diamond layer.