Sharp-to-Broad Band Energy Transfer in Lithium Aluminate and Gallate Phosphors for SWIR LED
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Short-wave infrared (SWIR) phosphor-converted light-emitting diode (LED) technology holds promise for advancing broadband light sources. Despite the potential, limited research has delved into the energy transfer mechanism from sharp-line to broadband emission in SWIR phosphors, which remains underexplored. Herein, we demonstrate bright SWIR phosphors achieved through Cr 3+ /Ni 2+ energy transfer in LiGa 5(1– x ) Al 5 x O 8 . High-resolution X-ray diffraction revealed the typical solid solution and distortion occurring in Al 3+ octahedral sites. In addition, the X-ray absorption spectrum illustrates that Cr 3+ and Ni 2+ have different coordination environments, showing the possibility that they occupy different positions or that the coordinated environment of Ni 2+ is distorted due to charge imbalance. Temperature-dependent studies provide insights into the energy transfer dynamics between Cr 3+ /Ni 2+, from the 2 E level of Cr 3+ (sharp band) to the 3 T 1 level of Ni 2+ (broadband). The increased emission intensity at lower temperatures in the x = 0.6 and x = 1.0 samples can be explained by the positioning of the 3 T 1 level above the 2 E level of Cr 3+ ions. Finally, we established a mechanism involving a sharp line to broadband energy transfer showcasing a high-power SWIR LED with a radiant power of 21.45 mW.
Source: ACS Applied Optical Materials
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G5250894298, G550105032, G7569305816
OpenAlex ID: W4392385765