Reversible yellow-gray photochromism in potassium-sodium niobate-based transparent ceramics

Ferroelectric ceramics exhibiting photochromic behavior and reversible luminescence modulation are highly desirable for optoelectronic applications ranging from information storage, displays, anti-counterfeiting to photo-switching devices. Herein, Sm3+-doped lead-free 0.85(K0.5Na0.5)NbO3-0.15SrZrO(3) (KNN-SZ: Sm3+) transparent ferroelectric ceramic featuring a typical photochromic phenomenon is designed and demonstrated. Upon alternate illumination and thermal stimulus (220 degrees C for 1 min), the ceramic exhibits reversible yellow-gray coloration. Furthermore, a maximum relative reflectivity variation of 29 % and a large luminescence quenching of 65.4 % with superior fatigue resistance were achieved in KNN-SZ: Sm3+. Various in-situ illuminations and thermal treatments in different ambient conditions were carried out to bring insight into the trapping and detrapping processes involved in photochromic behavior. The KNN-SZ: Sm3+ photochromic ceramics have great prospect in optoelectronic devices expanding the applications of KNN-SZ ceramics into advanced multifunctional materials for devices integration beyond electrical energy storage, electrocaloric and piezoelectric effects.

Automated summary

A transparent ferroelectric ceramic doped with Sm3+ exhibiting typical photochromic phenomenon has been designed, showing reversible yellow-gray coloration and superior fatigue resistance. The ceramic with photochromic behavior holds great prospects in optoelectronic devices.