Top-down micro and nano structuring of wide bandgap semiconductors for ultraviolet photodetection†

Abstract

Solar blind ultraviolet (UV) photodetectors (PDs) based on III-nitrides, silicon carbide (SiC), and other wide bandgap semiconductors such as diamond and gallium oxide (Ga₂O₃) offer excellent device performance such as low dark current, high responsivity, high detectivity, and high UV/visible rejection ratio. The performance of the UV PDs can be further improved by implementing micro and nanostructures via enhanced light–matter interaction. This review paper primarily encompasses the detailed study and recent development of various approaches of dry and wet etching techniques to enable the formation of micro and nanostructures built on the aforementioned material systems. Applications of different etching techniques for the development of PDs have been reviewed subsequently. Finally, the major challenges and future direction of micro and nanostructured UV PDs are briefly discussed.