The –– codoped phosphor has been prepared by an instant product forming low-temperature combustion method and its structure has been analyzed by using XRD method and FESEM analysis. The vibrational modes and optical upconversion emission study has been performed by using the FTIR spectroscopy and 980 nm laser diode excitation respectively. The temperature sensing based on the optical heating produced on increasing the pump power density in the developed phosphor has been performed. The upconversion emission study shows six bands around , , , , , and corresponding to the , , , , , transitions of and ions, respectively. The color emitted from the different samples is observed to vary from bluish green to yellowish green region via pure green region. The rise and decay times for the and bands originating due to the ( ion) and transitions ( ion), respectively, for one of the samples have been monitored. With the suitable rare earth ions doping concentration the developed phosphor shows white light upconversion emission upon excitation at 980 nm.