A novel Sm3+ doped niobium silicate luminescent glass with high thermal stability for the temperature sensing and LED applications

Abstract

Niobium silicate based materials have become a research focus due to their interesting photoelectric properties. In this study, a series of 35SiO2-35Nb2O5-10Na2O-20K2O-xSm2O3 (with x = 0.2/0.4/0.6/0.8/1.0/1.2 mol%) luminous glasses were prepared and characterized. Presence of Si-O-Si and O-Nb-O bonds makes these glass samples to have extremely high thermal stability; and addition of alkali metal ions increases their disorder. The lower optical bandgap and higher Urbach energies obtained prove that it is conducive to the microenvironment of luminescence. They exhibit strong absorption in the ultraviolet region and small chromaticity shift at high temperature. Glass with x = 0.8 mol% has been found to have the highest emission intensity, 84.85% transmittance, and 98.83% color purity, which proves the feasibility of the prepared luminous glass as the red light composition of LED. Concentration quenching can be associated mainly to the nearest neighbor ion interaction; increase of Sm3+ concentration causes decreasing distance of luminescent ions. The temperature range of 298-423 K shows promising application potential in optical temperature measurement, with maximum absolute sensitivity of 0.521% K-1 and maximum relative sensitivity of 0.550% K-1 being observed. Unique properties observed for the Sm3+ doped niobium silicate glasses indicate their development value in the field of multifunctional materials.