Quantum Cutting in Ultraviolet B-Excited KY(CO3)2:Tb3+ Phosphors

Abstract

Highly efficient quantum cutting KY(CO3)2:Tb3+ 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(CO3)2:Tb3+ remained in the Tb3+ 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(CO3)2:0.7Tb3+ could reach 119%. However, the most efficient quantum cutting occurred at the 5K8 excited state in the cross-relaxation of 5K8 + 7F65D4 + 5D4. The Tb3+ content could be selected arbitrarily in the KY(CO3)2 host without any concentration quenching. Optimal quantum cutting concentrations of Tb3+ in KY(CO3)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.