Currently, luminescent materials can be found in many important devices, including optical sources, displays, lasers, data storage, dosimeters, high-speed luggage scanners, and CT scanners. In most cases, these are semiconductor materials consisting of a host lattice doped with an activator (transition or rare earth ion). Host matrices doped with rare earth elements and exhibiting luminescence initially caught the attention of scientists in the 1930s. However, more in-depth research into these materials started in the 1960s. In subsequent years, the interest in them has steadily grown due to the development of new applications and the evolving industrial requirements for known materials. One of the extraordinary properties of rare-earth-doped materials that demonstrate luminescence is upconversion emission. There is a strong demand for generating artificial UV light for purposes such as surface decontamination, photopolymerization, solar hydrogen production, and the treatment of skin diseases, including cancer. The current methods of UV generation are costly, inefficient, and harmful to the environment. Therefore, one of the innovative approaches for UV generation is visible-to-ultraviolet upconversion. The Pr3+ ion, which predominantly emits in the UVC range (100-280 nm), is the most unique and least-studied activator in this context.
In this study, crystallites of new phosphates doped with varying concentrations of Pr3+ were synthesized using the solid-state method. The structure, optical, and upconversion properties in the UV-vis range were examined. Methods for improving the intensity of upconversion emission will be discussed.
ACKNOWLEDGMENTS
This work was supported by the National Science Centre under Grant No. UMO-2021/41/B/ST5/03792, which is gratefully acknowledged. One of the authors, A. Grippa (Oleksandr Gryppa), is thankful to the Polish Academy of Sciences for their support via the PAN-NANU (PAS-NASU) program of scientists cooperating with INTiBS PAN.
