Realization of multiple luminescence manipulation in tungsten bronze oxides based on photochromism toward real-time, reversible, and fast processes

Abstract

To design and fabricate next generation phosphor related photophysical devices, achieving facilely tunable luminescence performance in phosphors is extremely significant owing to their great potential application in a wide variety of research areas. Although great progress has been made in the electric, magnetic, and pressure fields, there are still no investigations on multiple modulation of luminescence in single phosphors. In this work, a series of novel photochromic tungsten bronze oxides are successfully synthesized and apparent color variation from light yellow to dark brown triggered by oxygen vacancies and variable valence ion related color centers is observed. On activation by Eu³⁺ and Mo⁶⁺, dual characteristics, photoluminescence, and photochromism, as well as a strong coupling effect are realized in tungsten bronze oxides. More interestingly, for the first time, multiple, real-time, reversible, and fast regulation of Eu³⁺ and Mo⁶⁺ co-doped Ba₄Gd₂Ti₄Nb₆O₃₀ samples is demonstrated by manipulating the overlapping degree of excitation, emission, and absorption peaks. We believe that this work will shed new light on the artificial design of the conventional luminescence performance in the future, which may have great potential application in logic gates, sensors, switches, and anti-counterfeiting devices.