Mu-Huai Fang et al.RU-SHI LIU2021-08-032021-08-0320208974756https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080039623&doi=10.1021%2facs.chemmater.0c00101&partnerID=40&md5=f0a446e38bf767659c758e8279937417https://scholars.lib.ntu.edu.tw/handle/123456789/575834Recently, infrared (IR) light-emitting diodes (LEDs) have attracted considerable interest in the research field worldwide. IR phosphors, the basic materials utilized in LEDs, have become a research hotspot as well. Here, we introduce the high-quantum-efficiency IR ScBO3:Cr3+ phosphor, which provides a spectral range of emission from 700 to 1000 nm with a peak maximum at 800 nm. Electron paramagnetic resonance spectroscopy, with high element selectivity, was used to elucidate the unusual small peak in the photoluminescence spectrum. Phonon structure and electron-lattice interaction were well observed and discussed via temperature-dependent measurements. Moreover, the high quantum efficiency of 72.8% was achieved. To evaluate their potential practical application, phosphor-converted LED packages were designed, which revealed high stability and high output power of 39.11 mW. Furthermore, the fabricated IR LED demonstrated a remarkable ability to penetrate biological tissues. This study provides insights into the luminescent properties and the practical applications of IR LEDs. Copyright ? 2020 American Chemical Society.Efficiency; Electron spin resonance spectroscopy; Infrared devices; Light emission; Light emitting diodes; Paramagnetic resonance; Phonons; Phosphors; Photoluminescence spectroscopy; Tissue; Electron paramagnetic resonance spectroscopy; Electron-lattice interactions; High quantum efficiency; Infrared light emitting diodes; Luminescent property; Phosphor-converted leds; Photoluminescence spectrum; Temperature-dependent measurements; Quantum efficiency[SDGs]SDG7journal article10.1021/acs.chemmater.0c001012-s2.0-85080039623