Highly Efficient Broadband Near‐Infrared Emission in Cr3+‐Activated Organic Hafnium Chlorine for Multi‐Optoelectronic Applications

Abstract Cr 3+ ions doped broadband emission near‐infrared (NIR) phosphors are pertinent to widespread emerging applications and get rapid developed. However, it remains a challenge to simultaneously achieve highly efficient and broadband near‐infrared emission in Cr 3+ ions doped phosphors. Herein, the Cr 3+ ions firstly doped into organic–inorganic hafnium chlorine TEA 2 HfCl 6 (TEA = Tetraethylammonium, C 8 H 20 N), which show broadband emission at a range of 700–1300 nm, a full width at half maximum (FWHM) of 164 nm, and a high photoluminescence quantum yield (PLQY) of 60%. The organic–inorganic metal halides show huge advantages than traditional inorganic phosphors, like high luminescence efficiency, low temperature solution synthesis progress, and low cost, which provide an efficiency strategy for lighting industry. Based on these advantages, a high power NIR light emitting diode (LED) is fabricated by TEA 2 HfCl 6 :Cr 3+ with a high‐power 530 nm chip, which is used in food analysis, night vision, and biomedical imaging as a demonstration. This work indicates the feasibility of organic–inorganic metal halides as host materials for developing Cr 3+ ions emitting phosphor toward multi‐optoelectronic applications.