A Cr 3+-doped halide double perovskite Cs 2AgInCl 6:Cr 3+ is first reported which exhibits a broad near-infrared emission ranging from 850 to 1350 nm centered at 1010 nm with a FWHM of 180 nm.
Searching for high performance and broader applications of inorganic halide perovskites has drawn extensive attention. In this work, a Cr 3+-doped halide perovskite, Cs 2AgInCl 6:Cr 3+, which exhibits broadband near-infrared (NIR) emission is first obtained via the traditional high temperature solid-state reaction. A broad emission band ranging from 850 to 1350 nm centered at 1010 nm with a full-width at half-maximum (FWHM) of 180 nm is assigned to the spin-allowed 4T 2 → 4A 2 transition of octahedrally coordinated Cr 3+ ions in a very weak crystal-field environment. The excitation bands centered at 353, 565 and 800 nm can be attributed to the absorption of the Cs 2AgInCl 6 host, the Cr 3+ d–d transitions of 4A 2 → 4T 1 and 4A 2 → 4T 2, respectively. Upon 760 nm excitation, the photoluminescence quantum yield (PLQY) of Cs 2AgIn 0.9Cl 6:0.1Cr 3+ is about ∼22.03%. Cs 2AgInCl 6:Cr 3+ phosphors with such broadband NIR emission have potential in phosphor converted light emitting diodes (pc-LEDs) which have applications in bioimaging and biomonitoring.