In this project, we intend to develop novel up-conversion phosphors for UVC light-emitting diodes (UVC-LEDs), antimicrobial surface coatings, and membranes. This could improve the antimicrobial ultraviolet C (UVC) radiation applications. The obtained results will form the basis for a future EU Horizon proposal to expand the applicability of these technologies to devices for the successful combat of COVID-19 and other infectious diseases. In addition, the outcomes will improve the quality of Romanian science in the field and contribute to the growth of the innovative competencies of students. The project envisions the creation of new Pr³⁺-doped phosphors with an efficient upconversion of visible light to UVC radiation. The host materials will be chosen using a novel method that combines machine learning/artificial intelligence (ML/AI) and high-throughput calculations. In the first step, an ML/AI model will be built from existing literature data using a combination of compositional and structural descriptors. The calculations will then be applied to the large number of compositions stored in Pearson’s Crystal Database, and the resulting descriptors will be fed into the ML/AI model, which will predict the relevant optical properties. Finally, the best crystal hosts will be chosen based on chemical stability, bandgap, 4f² → 4f¹5d¹ Pr³⁺ transition energy, and a few other parameters for synthesizing effective phosphors. The selected crystal hosts and Pr³⁺ combinations will be synthesized as fine crystalline powders using conventional chemical methods and thoroughly characterized structural and optical. For the UVC-LED, surface coating, and membrane fabrications, three of the best Pr³⁺ phosphors will be used. The UVC-LEDs will be covered with Pr³⁺ phosphors in UV transparent resin coating on the chip surface. Biodosimetry will be used to figure out how well UVC-LEDs, surface coatings, and membranes kill microorganisms.

O1. Estimation of properties for inorganic visible to UVC upconversion phosphors containing Pr³⁺ via machine learning and high-throughput DFT calculations.
O2. Synthesis of inorganic visible-to-UVC upconverting phosphors containing Pr³⁺ ions.
O3. Fabrication of phosphor-converted UVC-LEDs, antimicrobial surface coatings and polymeric membranes.