Co-doping of Stibium and rare earth (Nd, Yb) in lead-free double perovskite for efficient near-infrared emission

A 2 BB’ X 6 double perovskite has recently been considered as a potential substitute for lead-based halide perovskite . In particular, the lead-free Cs 2 AgInCl 6 material possesses excellent moisture and thermal stability. However, the wide bandgap of the Cs 2 AgInCl 6 host limits its optical properties . Doping with active elements is a unique avenue to endow Cs 2 AgInCl 6 with excellent optical properties . Here, a strategy is proposed to explore the efficiency of near-infrared (NIR) emissions in Ln 3+ (Ln Nd, Yb) ions doped Cs 2 AgInCl 6 microcrystal by the codoping of Sb 3+ ion for the first time. The incorporation of Sb 3+ ion emerges a new optical absorption channel at a longer wavelength (>350 nm) and reduces the electron bandgap. Under the excitation at 365 nm, Sb 3+ and Ln 3+ (Ln Nd, Yb) co-doped Cs 2 AgInCl 6 show the efficient NIR emission peaking at around 1000 nm, attributing to the effective energy transfer from Sb 3+ to Yb 3+ or Nd 3+ f-electrons. Accordingly, the photoluminescence mechanism and environmental stability of Sb 3+ and Ln 3+ (Ln Nd, Yb) co-doped Cs 2 AgInCl 6 microcrystal were also discussed in detail. This work demonstrates the availability of the Sb 3+ doping tactics to realize efficient NIR emission in Ln 3+ (Ln Nd, Yb) doped Cs 2 AgInCl 6 microcrystal.