S&M2611 Research Paper of Special Issue
Published: June 24, 2021
Near-infrared Phosphors: Photophysical Properties of Calcium-doped YSGG:Cr4+ [PDF]
Takayuki Nakanishi, Makoto Tsurui, Jian Xu, Nao Takahashi, Takashi Takeda, and Naoto Hirosaki
(Received January 30, 2021; Accepted May 10, 2021)
Keywords: garnet, near-infrared, chromium, luminescence
Toward developing super-broadband LEDs using NIR phosphors, the effect of Ca substitution on the luminescence of Cr-doped Y3Sc2Ga3O12 garnet (YSGG) was evaluated. The valence of chromium ions in YSGG mainly takes two states, trivalent and tetravalent, and YSGG shows luminescence peaks at 740 nm (Cr3+) in octahedral Sc sites and at 1530 nm (Cr4+) in distorted tetrahedral Ga sites. The garnet host is very suitable for optical-sensing LED applications because these two emission bands closely match two NIR windows, NIR-I (600–950 nm) and NIR-III (1500–1800 nm), which are applied for bio-imaging. In this study, we demonstrated that the Cr4+ broad emission was improved by Ca substitution to control the photophysical properties. We concluded that YSGG:Cr4+ with D2d symmetry in a unique distorted tetrahedron is a promising NIR phosphor for light-emitting applications.Corresponding author: Takayuki Nakanishi
This work is licensed under a Creative Commons Attribution 4.0 International License.
Cite this article
Takayuki Nakanishi, Makoto Tsurui, Jian Xu, Nao Takahashi, Takashi Takeda, and Naoto Hirosaki, Near-infrared Phosphors: Photophysical Properties of Calcium-doped YSGG:Cr4+, Sens. Mater., Vol. 33, No. 6, 2021, p. 2227-2234.