IR luminescence of CaGa2O4 : Yb3+ when excited by radiation with a wavelength of 940 and 980 nm

Abstract

The article provides an overview of known luminescent materials based on calcium gallate CaGa 2 O 4 , emitting in the visible and infrared (IR) spectral regions. IR phosphors have not been studied much, but their practical application is of interest. The solid-phase method was used to obtain CaGa 2 O 4 samples activated with rare-earth ions Yb 3+ . The structural and luminescent properties of the composition CaGa 2 O 4 : Yb 3+ were studied. When CaGa 2 O 4 : Yb 3+ was excited by radiation with a wavelength of 940 and 980 nm, luminescence was recorded in the range of 980—1100 nm. Based on data on the structure of electronic levels in Yb 3+ ions, it is concluded that excitation and radiation occur directly in Yb 3+ ions with the passive participation of the base lattice. Three maximums at a wavelength were recorded on the luminescence spectra: 993 nm, 1025 nm, 1080 nm. The radiation in these bands is due to optical transitions of electrons from the excited to the ground state in Yb 3+ ions. The dependence of the luminescence intensity in the 993 nm band on the concentration of Yb 3+ activator ions was studied. It found that the introduction of the phosphor ions Na + increases the intensity of the infrared luminescence. An optimal composition of the phosphor (Ca 1-x-y Yb x Na y )Ga 2 O 4 is proposed, at which the luminescence intensity in the range of 980—1100 nm is maximum.