https://phys.org/news/2018-07-uv-narrow-band-photodetector-based-indium.html > Narrow-band UV photodetectors find application in many areas, in particular in biomedicine where they are used for fluorescence detection or UV phototherapy. The materials commonly used in the manufacture of such photoreceivers are wide-bandgap oxides and nitrides, which offer a greater range of operating temperatures and transparency for visible and solar light in addition to a smaller size of the device. > Indium oxide (In2O3) is a transparent wide-bandgap semiconductor oxide with a direct band gap of about 3.6 eV and an indirect band gap of ~ 2.5 eV. It is well known that highly sensitive UV photodetectors can be created based on In2O3.