Mechanically induced enhancement and modulation of upconversion photoluminescence by bending lanthanide-doped perovskite oxides

We report experimental studies of the bending strain impact on the upconversion processes in Yb 3+ , Er 3+ , and Mn 2+ co-doped BaTiO 3 (BTO) thin films with mica as the flexible substrate. Bending strain induces strong enhancement and modulation of the upconversion emission in doped BTO thin films. Because the unshielded 3d 5 configuration of Mn 2+ is more susceptible to crystal field changes, the introduction of an Mn 2+ ion further promotes the strain-induced modulation effect. The upconversion intensity is amplified by six times at bending strain ε = 1.83% in BTO:Yb 3+ /Er 3+ /Mn 2+ thin films. These results demonstrate the opportunity of rendering an upconversion emission through integrating lanthanide-doped ferroelectric films with flexible mica, especially by incorporating an Mn 2+ ion.