Ultra-Broadband Near-Infrared Luminescence from a Vanadium-Activated Phosphate Glass

Broadband near-infrared (NIR) emitting materials have gained considerable attention for their applications in lighting, displays, sensing, bio-imaging, and optical amplification. Recently, numerous excellent broadband NIR emitting materials are developed by introducing Cr 3+ , Bi + , or Ni 2+ ions to various hosts. However, there is a notable absence of reports on ultra-broadband NIR emitters spanning the entire telecommunication window as well as the NIR-I (700–1000 nm) and NIR-II (1000–1700 nm) biological windows activated by vanadium ions. Herein, the study presents, for the first time to the best of the knowledge, ultra-broadband NIR emission ranging from 850 to 1600 nm (peaking at ≈1000 nm) at room temperature in vanadium-doped phosphate glass. Detailed spectra and microscopic structure analysis reveal that two V 3+ -emitting centers predominantly contribute to the ultra-broadband emission, corresponding to 3 T 2 ( 3 F)→ 3 A 2 ( 3 F) spin-allowed and 3 T 2 ( 3 F)→ 1 E( 1 D) spin-forbidden electron transitions of tetrahedrally coordinated V 3+ ions. Notably, the tunability of NIR emission peak is demonstrated by adjusting the local glass structure or the vanadium doping content. Moreover, glass-converted light-emitting diodes (gc-LEDs) are fabricated from vanadium-doped glass, and the potential applications are demonstrated. The work opens new avenues for the design and fabrication of broadband NIR-emitting materials and opto-electronic devices.