[Indirect sensitized upconversion in Tm3+ and Yb3+ codoped non-crystal pentaphosphate]

Area of Science:

• Materials Science
• Photonics
• Luminescence

Context:

• Upconversion luminescence allows materials to emit higher energy photons when excited by lower energy photons.
• Rare-earth ions like thulium (Tm3+) and ytterbium (Yb3+) are crucial for efficient upconversion processes.
• Non-crystal pentaphosphate materials offer unique host properties for luminescent applications.

Purpose:

• To investigate the blue upconversion luminescence properties of Tm3+ and Yb3+ codoped non-crystal pentaphosphate.
• To understand the underlying energy transfer mechanisms and the role of phonons in the upconversion process.
• To explore the potential of these materials for photonic applications.

Summary:

• Blue upconversion luminescence was observed in Tm3+ and Yb3+ codoped non-crystal pentaphosphate when pumped with a 798nm laser diode.
• Direct excitation to the Tm3+ 3F4 level followed by two energy transfer processes involving Yb3+ ions primarily populate the Tm3+ 1G4 level.
• Phonon interactions significantly influence the efficiency of the observed upconversion luminescence.

Impact:

• Demonstrates a novel material system for generating blue light via upconversion.
• Provides insights into the fundamental mechanisms governing rare-earth ion codoping for luminescence.
• Highlights the importance of host material selection and phonon engineering in optimizing upconversion efficiency.