Enhanced Responsivity of Diamond UV Detector Based on Regrown Lens Structure

In this work, the regrowth method is used on lens-structure diamond ultraviolet (UV) detector to suppress the surface defects caused by the lens fabrication process. After the regrowth of thin diamond film, the structure of the lens remains. Therefore, in the UV region, the regrown lens detector exhibits the highest responsivity compared with the original lens detector and the regrown planar detector. Moreover, the regrown lens detector two response peaks at around 240 nm and 240 nm. Under 220 nm or 240 nm illumination, the regrown lens detector display a fast response speed without obvious persistent photoconductive effect. This provides an efficient way to extend the the detection range of diamond UV detector while not sacrificing the performance of transient response.