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Unlocking Cr 3+ -Cr 3+ Coupling in Spinel: Ultrabroadband Near-Infrared Emission beyond 900 nm with High Efficiency and Thermal Stability.
- Source :
-
ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2024 Jun 12; Vol. 16 (23), pp. 30185-30195. Date of Electronic Publication: 2024 May 31. - Publication Year :
- 2024
-
Abstract
- Broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) hold promising potential as next-generation compact, portable, and intelligent NIR light sources. Nonetheless, the lack of high-performance broadband NIR phosphors with an emission peak beyond 900 nm has severely hindered the development and widespread application of NIR pc-LEDs. This study presents a strategy for precise control of energy-state coupling in spinel solid solutions composed of Mg <subscript> x </subscript> Zn <subscript>1- x </subscript> Ga <subscript>2</subscript> O <subscript>4</subscript> to tune the NIR emissions of Cr <superscript>3+</superscript> activators. By combining crystal field engineering and heavy doping, the Cr <superscript>3+</superscript> -Cr <superscript>3+</superscript> ion pair emission from the <superscript>4</superscript> T <subscript>2</subscript> state is unlocked, giving rise to unusual broadband NIR emission spanning 650 and 1400 nm with an emission maximum of 913 nm and a full width at half-maximum (fwhm) of 213 nm. Under an optimal Mg/Zn ratio of 4:1, the sample achieves record-breaking performance, including high internal and external quantum efficiency (IQE = 83.9% and EQE = 35.7%) and excellent thermal stability ( I <subscript>423 K</subscript> / I <subscript>298 K</subscript> = 75.8%). Encapsulating the as-obtained phosphors into prototype pc-LEDs yields an overwhelming NIR output power of 124.2 mW at a driving current of 840 mA and a photoelectric conversion efficiency (PCE) of 10.5% at 30 mA, rendering high performance in NIR imaging applications.
Details
- Language :
- English
- ISSN :
- 1944-8252
- Volume :
- 16
- Issue :
- 23
- Database :
- MEDLINE
- Journal :
- ACS applied materials & interfaces
- Publication Type :
- Academic Journal
- Accession number :
- 38818828
- Full Text :
- https://doi.org/10.1021/acsami.4c03419