Improved detection of the invisible

The ultraviolet (UV) portion of the spectrum is widely used for a variety of sensing and imaging applications. However, until very recently, with the advent of wide-bandgap materials such as AlGaN, there have not been high-performance optoelectronic devices designed for optimal operation in the UV range. Thus, the development of sophisticated detection applications in the UV range has been limited by the existing technology. This article outlines recent advances in the development of high-quality UV photodetectors fabricated on GaN and AlGaN. Several specific device structures and their performance characteristics are also presented.