Up-conversion luminescence regulation and its boosting by polarization in Er3+/Yb3+ doped SrBi8Ti7O27 photochromic ceramics for optical switching application

Highlights: • A class of smart SrBi₈Ti₇O₂₇ based phosphor was developed. • UC reversible regulation was achieved accompanying with photochromic process. • Polarization treatment was an effective way to improve UC modulation performance. • SrBi₈Ti₇O₂₇ based phosphor has promising application in optical switching field. -- Abstract: The various applications of luminescence materials were generally based on the effective modulation of luminescence spectra. However, the research on reversible spectral regulation of up-conversion (UC) luminescence materials was still in its infancy stage. In this work, a class of smart phosphor, Er³⁺ and Yb³⁺-codoped SrBi₈Ti₇O₂₇ (SBYT: xEr³⁺) intergrowth bismuth layer-structured ferroelectric, possessing fast sensitivity to visible light irradiation, was reported based on visible light driven photochromic effect. Through the alternate stimuli of light irradiation and heating treatment, the reversible regulation of UC luminescence was achieved accompanying with the switching of coloration and decoloration processes. The luminescence modulation degree tightly relied on the irradiation time and thermal treatment modes. The reversibility and stability properties were also revealed. Moreover, it is found that polarization treatment was an effective approach which can be adopted to improve the UC luminescence contrast. The maximum luminescence modulation ability of SBYT: xEr³⁺ reached up to 81.3% which was 131% of that un-polarized sample. It is believed that SBYT: xEr³⁺ ceramics can act as a promising candidate for optical data storage and anti-counterfeiting applications.