Defect Management and Multi-Mode Optoelectronic Manipulations via Photo-Thermochromism in Smart Windows

Smart windows with adjustable transmittance via physical stimuli are eagerly desired for sorts of energy-saving lighting systems. However, reciprocal trade-off relationship such as high transparency and coloration/discoloration ability exists in smart windows, not conducive to optical-electrical coupling and leap in performance. Substituting for common composites utilized in smart windows, here, single transparent ceramic-based smart windows are reported through composition design and defect management strategies to regulate the optoelectronic performances and break off the contradictions between optical transmittance, photo-thermochromism and electrical conductivity. By first principles calculations and precisely tuning Er³⁺, Ba²⁺, Sr²⁺ concentrations in non-stoichiometric Er-doped (K_0.5Na_0.5)NbO₃-(Ba, Sr)TiO₃, the fabricated ceramics exhibit brilliant transparency and multi-mode dramatical and reversible modulations of pellucidity, photoluminescence intensity, along with conductivity (over fivefold variation), enabling prominent optoelectronic information storage and modulating capacity in vivid potential applications, such as easy-readout/erasable optical memorizers, photo-memristors and anti-counterfeiting displays.