Luminescence performance and vibronic behavior of Mn4+-activated Ca14-xKxAl10-xZn6O35 deep-red phosphor

In this study, a significant improvement of deep-red luminescence was successfully achieved via the substitution approach in the Mn4+-activated Ca14-xKxAl10-xZn6O35 phosphor. The optimal Mn4+ doping level x was determined by studying luminescence concentration quenching behavior. The measured photoluminescence (PL) spectrum showed five distinct vibronic structures with the main peak centered at 712 nm. A theoretical simulation work was conducted for comparison, and the predominant phonon mode involving in the vibronic transition process was revealed. From the temperature dependent PL spectra, an abnormal luminescence enhancement was observed at the temperature rising from T=100 to 340 K, and the underlying phonon-assisted luminescence mechanism was theoretically disclosed. Finally, we studied the temperature dependent luminescence lifetime, and the primary phonon energy in the vibronic behavior was identified from the fitting work.