Pumping-route-dependent concentration quenching and temperature effect of green up- and down-conversion luminescence in Er3+/Yb3+ co-doped Gd2(WO4)3 phosphors

Abstract Gd 2 (WO 4 ) 3 phosphors with various Er 3+ concentrations and fixed Yb 3+ concentration were synthesized via a co-precipitation method, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The concentration quenching behaviors of green up- and down-conversion emissions of Er 3+ were analyzed, and it was confirmed that the difference between quenching concentration for up- and down-conversion emissions resulted from the different population routes. The temperature sensing properties of the Gd 2 (WO 4 ) 3 :Er 3+ /Yb 3+ phosphors were studied, and it was found that the Er 3+ doping concentration slightly affected the sensitivity, and Gd 2 (WO 4 ) 3 :Er 3+ /Yb 3+ phosphors could be used in a broad temperature region for detecting temperature. Finally, the thermal effect induced by 980 nm LD irradiation was investigated, it was observed that the equilibrium temperature of Gd 2 (WO 4 ) 3 :Er 3+ /Yb 3+ sample was decided by both the excitation power and Er 3+ doping concentration.