Broadband Near‐Infrared Garnet Phosphors with Near‐Unity Internal Quantum Efficiency. Issue 12 (20th April 2020)

• Record Type: Journal Article
• Authors: Basore, Endale T.; Xiao, Wenge; Liu, Xiaofeng; Wu, Jianhong; Qiu, Jianrong
• Is Part Of: Advanced optical materials. Volume 8:Issue 12(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-20
• Subjects: Cr 3+ -- garnets -- light‐emitting diodes -- near‐infrared emission -- phosphors; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202000296
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Compact near‐infrared (NIR) light sources with broad emission band are essential to enable NIR spectroscopy compatible with portable devices, and phosphor‐converted light emitting diodes (pc‐LEDs) are efficient, low‐cost, and compact light sources. However, it is more challenging to develop highly efficient and thermally stable broadband NIR phosphors than conventional phosphors for white LEDs. Here, a series of solid solution phosphors with broadband NIR emission designed by cationic substitution in Cr 3+ activated garnet Gd3 Sc2 Ga3 O12 are reported. The internal quantum efficiency of Cr 3+ emission can be significantly improved to nearly 100% via the substitution of ScO6 with smaller AlO6 octahedrons, which is attributed to the reduction of antisite defects. Moreover, the phosphor with optimized composition shows highly thermally stable emission, which renders the as‐fabricated pc‐LED with high‐power (750.8 mW) NIR emission covering the wavelength range of 700–1000 nm. The results could advance the development of NIR pc‐LEDs as high‐performance light sources for miniature NIR spectrometers. Abstract : Broadband near‐infrared (NIR) phosphors with near‐unity internal quantum efficiency and high thermal stability are developed via the cation substitution of Sc 3+ with smaller Al 3+ to reduce the antisite defects of Cr 3+ doped Gd3 Sc2 Ga3 O12 . Phosphor‐converted light emitting diodes (LEDs) with high‐power broadband NIR emission could serve as a compact light source for miniature NIR spectrometers.