Sol-gel auto-combustion preparation and photoluminescence properties of Er3+-doped K2La2Ti3O10 phosphors with superior thermal luminescence stability.

Thermal luminescence quenching behavior was observed from the temperature-dependent emission spectra under 383 nm excitation. The emission intensity of Er3+ at 423 K still remained about 67.0% of the initial value at 303 K, revealing that this kind of phosphor possessed superior thermal luminescence stability. The activation energy was determined to be about 0.188 eV. It was found that the temperature sensitivity of Er3+ was sensitive to the doping concentration of Er3+. The lower the concentration of Er3+ was, the higher the temperature sensitivity was. Thermal luminescence property is one of the important factors to evaluate the performance of the phosphors. In this work, a series of Er3+-doped K 2 La 2 Ti 3 O 10 phosphors were synthesized by a sol-gel auto-combustion method. The crystal structure, surface morphology, luminescence performance, thermal stability, and temperature sensing properties were investigated in detail. All samples exhibited green emissions around 530 and 564 nm due to the 2H 11/2 , 4S 3/2 →4I 15/2 transitions of Er3+ upon 383 nm excitation. The optimal doping concentration of Er3+ was about 3 mol%. Electric dipole-dipole interaction was determined to be the main mechanism for the concentration quenching of Er3+ and possible cross-relaxation routes were proposed. Thermal luminescence quenching behavior was observed from the temperature-dependent emission spectra, and the results showed that K 2 La 2 Ti 3 O 10 : Er3+ phosphors had superior thermal luminescence stability. The activation energy was determined to be about 0.188 eV. Moreover, it was found that the temperature sensitivity of Er3+ in K 2 La 2 Ti 3 O 10 : Er3+ phosphors was sensitive to the doping concentration of Er3+. The lower the concentration of Er3+ was, the higher the temperature sensitivity was. [ABSTRACT FROM AUTHOR]