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. A diamond p–i–n junction structure is fabricated with the microwave plasma chemical vapor deposition method, and it is applied for UV detection. The p–i–n junction detector shows a high responsivity and obvious spectral selectivity between UV light and visible light. The use of n‐type diamond layer causes a long response time and is necessary to be optimized.