Tunable Ho3+co-doped YOF:Bi3+emission through cathodoluminescence

The tunability of holmium (Ho3+) emission was achieved with bismuth (Bi3+) as a co-dopant in an yttrium oxyfluoride (YOF) host for optoelectronic applications. Cathodoluminescence (CL) studies were investigated under electron beam irradiation (5 keV) for both YOF: x mol % Bi3+ (x = 0.3, 0.4, 0.5, 0.6, 0.8) and YOF: 0.4 mol % Bi3+, x mol % Ho3+ (x = 0.8, 1.4, 2, 3, 4, 5) samples. The samples were synthesized by the pyrolysis technique followed by annealing in ambient air at 900 degrees C. The structure of all samples exhibited pure rhombohedral YOF. The morphology studies showed small particles that agglomerated into bigger particles after annealing. Ultra-violet CL emission for the single doped Bi3+ samples were attributed to the emission of Bi3+ around 316 nm and the visible emission around 624 nm was attributed to Bi2+. The presence of Bi2+ emission was a result from ionization during electron beam bombardment. The samples co-doped with Bi3+ and Ho3+ ions showed the same emission components of Bi3+ and Bi2+ as well as Ho3+ emission at 540 nm. X-ray photoelectron spectroscopy confirmed the samples' composition with the presence of Bi2+ as well as the existence of an intermediate Y-O-F layer that must have formed during electron bombardment. The fitted CIE coordinates of the co-doped samples showed that the CL emission can be tuned from green to yellow and to orange.

Automated summary

The tunability of holmium (Ho3+) emission was achieved by co-doping bismuth (Bi3+) with an yttrium oxyfluoride (YOF) host for optoelectronic applications. The samples were synthesized using the pyrolysis technique followed by annealing in ambient air at 900 degrees C. The co-doped samples exhibited emission components of Bi3+, Bi2+, and Ho3+, with the cathodoluminescence (CL) emission tunable from green to yellow and to orange.