LUMINESCENT PROPERTIES OF GLASS Ag2S-GeS2 AND Ag2S-GeS2-Sb2S3 DOPED WITH ERBIUM AND NEODYMIUM

Abstract

Chalcogenide glasses doped with rare earth metals have unique properties. They are used as light-emitting media in laser technology, switches, optical sensors, for the construction of rangefinders in military equipment, air pollution monitoring, etc. The sulfur-containing glasses studied in the article are characterized by transparency in the visible part of the spectrum, as well as in the near and middle spectral range. By introducing rare earth metals impurities into such wide-gap semiconductors, it is possible to obtain materials with specified optical properties, in particular, with a high quantum yield of radiation. In the presented work, the composition of the samples, into the glass matrix of which 2% Nd2S3 and (1-4)% Er2S3 could be introduced, is given. Glasses Ag2S-GeS2-Nd2S3-Er2S3 and Ag2S-GeS2-Sb2S3-Nd2S3-Er2S3 were synthesized by the solution-melt method. Photoluminescence bands in the near-infrared range of the spectrum were recorded when the samples were excited using a laser with an energy of 1.54 eV. The emission maxima of 1.16 and 0.92 eV correspond to transitions 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 in f-shells of ions Nd3+. Photoluminescence, which is associated with erbium ions, has not been recorded. The position and shape of the maxima does not change when the concentration of rare earth metals changes. An increase in the erbium content leads to a decrease in the intensity of the radiation maxima. We attribute this effect to the processes of energy transfer between Nd3+ and Er3+ ions when the concentration of the latter increases. Based on the diagram of energy levels in neodymium ions, the mechanism of excitation and emission in Nd3+ ions is discussed. The emergence of intense photoluminescence bands in the Ag2S-GeS2 and Ag2S-GeS2-Sb2S3 systems glasses doped with erbium and neodymium can be used to design lasers in the near-infrared range of the spectrum.