Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by h...Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by high temperature calcination,with precursor powder obtained by hydrothermal method.Strong red emission at 615 nm was observed which corresponds to the 5D0→7F2 transition of Eu3+under excitation of 465 nm.Under UV light irradiation for 3 min,the color of the ceramics turned from milky white to dark gray.The colored samples returned to the original color when heated at 200℃for 10 min,showing strong photochromic behavior.Meanwhile,the luminescence intensity of Eu3+can be tuned without obvious degradation by alternating UV light and heat stimulus.Upon UV light irradiation,large luminescence modulation ratio(ΔRt)up to 83.9%was achieved for KNN:0.06Eu,indicating good luminescence switching behavior.A possible mechanism for non-radiative energy transfer from the luminescent center to the color center was proposed according to their luminescent behavior.展开更多
基金National Natural Science Foundation of China(61605116,51972213)Science and Technology Commission of Shanghai Municipality(15ZR1440600,15520503400)。
文摘Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by high temperature calcination,with precursor powder obtained by hydrothermal method.Strong red emission at 615 nm was observed which corresponds to the 5D0→7F2 transition of Eu3+under excitation of 465 nm.Under UV light irradiation for 3 min,the color of the ceramics turned from milky white to dark gray.The colored samples returned to the original color when heated at 200℃for 10 min,showing strong photochromic behavior.Meanwhile,the luminescence intensity of Eu3+can be tuned without obvious degradation by alternating UV light and heat stimulus.Upon UV light irradiation,large luminescence modulation ratio(ΔRt)up to 83.9%was achieved for KNN:0.06Eu,indicating good luminescence switching behavior.A possible mechanism for non-radiative energy transfer from the luminescent center to the color center was proposed according to their luminescent behavior.
