Rapid high-contrast reversible coloration of Ba3MgSi2O8:Pr3+ photochromic materials for rewritable light-printing

Designing a "rewritable paper" is an effective and feasible method to solve the environmental problems caused by paper consumption. Inorganic ferroelectrics and robust oxide photochromic materials exhibit excellent reversible print/erase responses, a fast response time, and outstanding physical and chemical stability, which are vital for the implementation of a rewritable paper. However, the application of "rewritable paper" based on these inorganic photochromic materials is limited by its low color contrast. In this study, an ultra-high color contrast of 77.1% is obtained through inducing oxygen vacancy defects in Ba3MgSi2O8:0.5%Pr3+ by ion doping and sintering in a reducing atmosphere. The rewritable paper fabricated with Ba3MgSi2O8:0.5%Pr3+ shows a reversible write and erase response under UV illumination and thermal stimulus and also shows the advantages of a fast response time and excellent color reversibility. Furthermore, due to a good overlap between the absorption peak of Ba3MgSi2O8 and the excitation/emission peak of Pr3+, a large luminescence modulation of 97.9% can be obtained in Ba3MgSi2O8:0.5%Pr3+, which has a wide application prospect in anti-counterfeiting displays and easy-readout/erasable photo-memorizers. The insights provided will support fellow researchers to design high-performance inorganic photochromic systems by inducing oxygen vacancies.