About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Solid-State Optical Materials and Luminescence Properties
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| Presentation Title |
Stabilizing Mn5+ in High Optical Basicity Glasses: A New Class of NIR-II Phosphors for Bioimaging |
| Author(s) |
Amir Ashjari, Jiao Li, Danielle Perry, Brian Topper, Yiquan Wu, Doris Möncke |
| On-Site Speaker (Planned) |
Amir Ashjari |
| Abstract Scope |
This study demonstrates the first stabilization of Mn5+/Mn6+ ions within high-optical-basicity silicate and borate glasses, offering a new class of amorphous NIR-II phosphors. Guided by the optical basicity concept developed by Duffy and Ingram, we synthesized Mn-doped M2O–NO–SiO2 glasses (M = K, Cs; N = Ca, Ba, Sr) with optical basicities ranging from 0.72 to 0.82. Optical spectroscopy revealed a shift from Mn3+ toward Mn5+/Mn6+ as the basicity increased. Photoluminescence measurements confirmed a narrow NIR-II emission (~1190 nm) characteristic of tetrahedral Mn5+, with bi-exponential decay lifetimes reaching up to 250 μs. Resonance Raman spectroscopy identified strong Mn-O stretching vibrations ~800 cm-1, corroborating the formation of MnO43-/MnO42-. These results establish high-basicity glasses as the first amorphous systems capable of stabilizing Mn6+ in addition to Mn5+, providing tunable and biocompatible platforms for NIR-II bioimaging and thermometry. Ongoing work focuses on enhancing chemical durability through compositional optimization and developing core-shell nanostructures. |