PART 1: NON-TECHNICAL SUMMARY Trivalent cerium (Ce(III)) doped optical materials possess extraordinary optical and physical properties and currently represent the state-of-art materials for advanced optical devices that are used in medical imaging, high-energy particles and radiation visualization, measurement time of particles arrival in colliding beam experiments, neutrino and dark matter detectors, and optical elements resistant to high levels ionizing radiation for critical infrastructure and communication, and illumination. Presently, most existing highly Ce(III)-doped materials for the above-mentioned applications are based on crystalline solids (were the atoms are well ordered within the structure) because of their ability to accommodate large concentrations of the Ce(III) ions. However, the fabrication processes for these highly doped crystals are complex, time-consuming, and expensive, particularly when compared with similar composition glasses (where atoms are short-range ordered but disordered within long range). Similarly, applications of such crystals is also restricted by small size, brittleness, and change in physical properties with orientation. All these challenges can be addressed by use of highly Ce(III)-doped silicate glasses that offer improvements in mechanical properties, chemical durability and thermal stability compared ot their crystalline counerparts and can be made into large-size and complex shapes (including drawn into optical fibers, extensively used in current photonic systems). However, the doping levels of Ce(III) in silicate glass systems are typically very low due to poor stability of Ce(III) ions, limiting their range of applications. The aim of this research is to enhance the stability of these cerium ions within silicate glass to achieve unprecedented levels of doping. Novel synthesis procedures of Ce(III)-doped boron-aluminosilicate glass will be employed to understand and explore factors influencing stability of Ce(III) ions. The effect of Ce(III) doping level and synthesis conditions on physical, optical and luminescent properties of boron-aluminosilicate glasses will be systematically studied. The gained knowledge will aid in developing cost-efficient and robust highly Ce(III) -doped materials for advanced photonic applications. The project will provide an interdisciplinary training experience to graduate students in material and optical sciences. The investigators and graduate students involved in this project will further emphasizes educational outreach, aiming to enhance interest in material and optical sciences by offering research experiences and mentorship to undergraduate students. PART 2: TECHNICAL SUMMARY The planned research is centered on pushing the current doping limits of Ce(III)-doped materials well beyond the 1 mol.% of Ce2O3 range currently achievable. High doping levels of Ce(III) ions in optical materials are usually required for low cost, size, weight, and power photonic devices and have been mostly achieved with crystalline materials. However, such heavily doped crystals cannot be produced in bulk or have too expensive and time-consuming manufacturing processes. Compared to the above, silicate glasses are an ideal host for Ce(III) ions with advantages of low-cost, ease of production and scaling, melt-cast into multiple shapes, and would have favorable mechanical properties, chemical durability and thermal stability. Although numerous efforts have been made to incorporate Ce(III) into robust silicate glass systems, the doping level of Ce(III) is still limited to less than 3.7×10^20 Ce(III) ions/cm3 before Ce(IV) appears, making Ce(III)-doped glass material non-competitive against crystals. To obtain highly Ce(III)-doped boron-aluminosilicate glass (10^22 ions/cm3) a systematic study of the effects of synthesis conditions, precursor chemicals and additives on cerium (III) to cerium (IV) transition and the glass physical properties is proposed. Additional focus is placed on the characterization of the developed glass materials, through study of optical, spectral, luminescence, magneto-optical and scintillation properties, defect formation under gamma rays, as well as energy transfer in Tb (III), Eu(III) and Mn(II,IV) co-doped samples are being studied to evaluate the performance. This research approach provides an excellent opportunity for graduate students to learn cutting edge experimental techniques and theoretical methods used in material and optical research and gain a broader understanding of how material and optical sciences can address some of society?s major challenges, e.g., affordable medical services, nuclear waste management and security. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.