Structure- and temperature-sensitive photoluminescence in a novel phosphate red phosphor RbZnPO4:Eu3+

Abstract

A novel phosphate RbZnPO₄ has been developed for the first time and the characteristic crystal structure of RbZnPO₄ has been investigated in detail, based on the Fourier transform infrared reflection spectra and the structure refinement of X-ray diffraction data. After doping with Eu³⁺,RbZnPO₄:Eu³⁺ shows distinctive deep red emission with dominating peaks at 596 and 701 nm. To provide a reasonable explanation for the relationship between photoluminescence and structure, the photoluminescence property has been discussed by analyzing the particular local ligand environment and site occupation of Eu³⁺ in RbZnPO₄. More interestingly, temperature-sensitive emission behavior was found in RbZnPO₄:Eu³⁺. Through the synthetical analysis of the configurational coordinate diagram, the charge compensation experiment and the CASTEP band structure calculation, a complex underlying mechanism is proposed to explain the abnormal temperature-sensitive emission behavior in RbZnPO₄:Eu³⁺. The mechanism could be helpful for better understanding the thermal quenching process of Eu³⁺ in RbZnPO₄ and also as a reference in some other temperature-sensitive phosphors.