Thermal analysis of phonons assisted bright yellow upconversion emission and one photon near-infrared upconversion emission in Nd3+ doped GdVO4 single crystals

Bright yellow upconversion emission spectra at 595 nm were investigated in Nd(3+ )ions doped gadolinium orthovanadate (GdVO4) single crystals. 556-fold enhancement of the intensity of upconversion emission at 595 nm was investigated at the sample temperature of 400( degrees)C, which followed the exponential increase with temperature. The lg-lg relationships of the detected upconversion emission spectra and the input pumping laser were discussed, which dropped to 2.28 at high temperature from 5.98 at low temperature and implied fewer photons are required at higher temperatures. Thermal phonon-assisted excitation and electron-phonon coupling activities played important roles in the one photon upconversion emission excited by the laser centered at 1064 nm, and over 3700-fold enhancement of the emission peaks at 756 nm was observed. The finding in this work provides thermal stability analysis in Nd3+ ions doped laser materials and expands rare earth ions upconversion mechanisms.