Chen, Kuan-ChunKuan-ChunChenHsiao, Yu-HsuanYu-HsuanHsiaoChien, Chun-LingChun-LingChienHuang, Wen-TseWen-TseHuangMajewska, NataliaNataliaMajewskaMazurek, Michał R.Michał R.MazurekLeśniewski, TadeuszTadeuszLeśniewskiMahlik, SebastianSebastianMahlikLeniec, GrzegorzGrzegorzLeniecCherng, Ding-HuaDing-HuaCherngLu, Kuang-MaoKuang-MaoLuHuang, Sheng-LungSheng-LungHuangLiu, Ru-ShiRu-ShiLiu2025-06-302025-06-302025-06-05https://scholars.lib.ntu.edu.tw/handle/123456789/730364A bifunctional (Ga,Ge)2O3:Cr3+,Ni2+ phosphor system for optical fiber amplifiers and light-emitting diode applications was investigated. By applying a solid-state reaction method, one Ga1.98-2xGexO3:0.02Cr3+,xNi2+ phosphor series is successfully prepared. The optimized composition demonstrated a broadband shortwave infrared (SWIR) emission at 1430 nm and a 10.6% absolute internal quantum efficiency value of Ni2+ emission. Electron paramagnetic resonance spectroscopy revealed detailed insights into the local environment of Cr3+ and its alteration by introducing Ni2+ dopants. When the laser-heated pedestal growth method was used, the grown crystal fibers exhibited promising characteristics for optical communication applications, particularly in the 1300-1600 nm telecommunication band. The dual functionality of the material was demonstrated by the fabrication of SWIR optical fiber amplifiers and light sources. This research introduces a versatile material platform that effectively addresses the challenges in optical fiber communications while offering new possibilities for SWIR light source applications.en[SDGs]SDG7journal article10.1021/acsenergylett.5c01251