Giant In3+ doping-induced enhancement of the upconversion luminescence of Ba0.85Ca0.15TiO3:Er3+/Yb3+ lead-free ferroelectric ceramics.

We synthesized In 3+ -doped Ba 0.85 Ca 0.15 TiO 3 :Er 3+ /Yb 3+ / x In 3+ lead-free ferroelectric ceramics that possess strong ferroelectricity and excellent upconversion luminescence under the excitation of 980 nm. With increasing x from 0, the green and red emission intensity increases and reaches the maximum at x =1.5% mol, then decreases slightly with further increase in x . For the x =1.5% sample the green emission intensity at 550 nm is ∼10 times larger than that of In 3+ undoped samples. Such a large In 3+ doping-induced enhancement of the luminescence is unprecedented for perovskite ferroelectrics. Based on the ultraviolet-visible-near infrared absorption spectra, the variation of the luminescence intensity with the In 3+ content was discussed. [ABSTRACT FROM AUTHOR]