Enhanced NIR region emission of chromium by changing the chromium concentration in yttrium aluminum garnet (YAG) host matrix

Abstract

The luminescence properties of yttrium aluminum garnet doped with variable chromium concentration were investigated under namely three different excitation wavelengths – 275 nm, 440 nm, and 580 nm. It was discerned that under 440 nm and 580 nm excitation, spin forbidden 2 E→ 4 A 2 transition shows a typical trend of increasing emission intensity with concentration increase in the range of 320–900 nm. Whereas, when the compounds with an increasing nominal dopant concentration were excited with 275 nm radiation, an exponential decrease in emission intensity of spin allowed 4 T 2 → 4 A 2 transition (in the range of 700–1000 nm) was observed. It was demonstrated that the emission of a single compound with one dopant exhibits emission in almost half of the NIR region. • Luminescence properties of YAG:Cr 3+ are investigated under 275 nm, 440 nm and 580 nm excitation wavelengths. • Material exhibits a reverse emission intensity dependence of 4 T 2 → 4 A 2 transition. • The discovery of this phenomenon might be utilized as a probe for chromium contamination in yttrium aluminum garnet.