The results of work on developing and studying ultraviolet (UV) light-emitting diodes (LEDs) based on GaN/AlGaN heterostructures fabricated on Al₂O₃(0001) substrates by the chloride-hydride vaporphase epitaxy are presented. The maximum in the electroluminescence spectrum is located in the wavelength range of 360–365 nm, and its full width at half maximum is 10–13 nm. At a working current of 20 mA, the optical density and efficiency of the UV LED are 1.14 mW and 1.46%, respectively.

The results of studies of porous materials based on various metal oxides (Fe2O3, ZnO, In2O3, etc.) by photoluminescence analysis and atomic force microscopy are reported. The influence of the...