Quantum Cutting in Ultraviolet B-Excited KY(CO(3))(2):Tb(3+) Phosphors

Highly efficient quantum cutting KY(CO(3))(2):Tb(3+) phosphors excited by ultraviolet B (UVB) and ultraviolet C (UVC) were investigated. The structural and spectroscopic properties were characterized by XRD analysis and fluorescence spectrophotometry, respectively. The results showed that the monoclinic crystal structure of KY(CO(3))(2):Tb(3+) remained in the Tb(3+) doping range of 0~100%. In the excitation spectrum, two intense excitation peaks were observed in the ultraviolet range. Under the excitation of 283 nm, the maximum quantum efficiency of KY(CO(3))(2):0.7Tb(3+) could reach 119%. However, the most efficient quantum cutting occurred at the (5)K(8) excited state in the cross-relaxation of (5)K(8) + (7)F(6)(5)D(4) + (5)D(4). The Tb(3+) content could be selected arbitrarily in the KY(CO(3))(2) host without any concentration quenching. Optimal quantum cutting concentrations of Tb(3+) in KY(CO(3))(2) were 0.7 and 0.3 for the excitation of UVB and UVC, respectively. UVB-excited phosphors are more popular with high transparency in products such as glass or resin. A quick response code was fabricated by resin to show the hidden information clearly. Therefore, the highly efficient phosphor could be a candidate material for the application in information identification technology.