Rajendran, VVRajendranChen, KCKCChenHuang, WTWTHuangMajewska, NNMajewskaLesniewski, TTLesniewskiGrzegorczyk, MMGrzegorczykMahlik, SSMahlikLeniec, GGLeniecKaczmarek, SMSMKaczmarekPang, WKWKPangPeterson, VKVKPetersonLu, KMKMLuChang, HoHoChangRU-SHI LIU2023-03-092023-03-0920232380-8195https://scholars.lib.ntu.edu.tw/handle/123456789/629075Manganese in the pentavalent state (Mn5+) is both rare and central in materials exhibiting narrow-band near-infrared (NIR) emission and is highly sought after for phosphor-converted light-emitting diodes as promising candidates for future miniature solid-state NIR light source. We develop the Ca14Zn6Ga10-xMnxO35 (x = 0.3, 0.5, 1.0, 1.25, 1.5, and 3.0) series that exhibit simultaneous Mn4+ (650-750 nm) and Mn5+ (1100-1250 nm) luminescence. We reveal a preferential occupancy of Mn in regular octahedral and tetrahedral environments, with the short bond length between these responsible for luminescence. We present a theoretical spin-orbital interaction model in which breaking the spin selection rule permits the luminescence of Mn4+ and Mn5+. A total photon flux of 87.5 mW under a 7 mA driving current demonstrates its potential for real-time application. This work pushes our understanding of achieving Mn5+ luminescence and opens the way for the design of Mn5+-based narrow-band NIR phosphors.enSTRUCTURAL EVOLUTION; ENERGY-TRANSFER; PHOSPHORS; EMISSION; SPECTRA; SPECTROSCOPY; MN4+[SDGs]SDG7journal article10.1021/acsenergylett.2c024032-s2.0-85143633276WOS:000898700300001https://api.elsevier.com/content/abstract/scopus_id/85143633276