Highly efficient and stable blue photoluminescence from environmental-friendly double perovskites

Despite intensive explorations, lead-free, low toxicity, efficient, and stable blue fluorescent materials are still highly desirable. Cs2NaInCl6 double perovskite (DP) is considered as a promising candidate for solid-state lighting due to its low toxicity and good stability. In this work, Mg-doped Cs2NaInCl6 DPs are prepared by a solvothermal method. The Mg2+-doped Cs2NaInCl6 DPs exhibit blue photoluminescence (PL) at about 445 nm with a full-width at half maximum of 58.0 nm, which is independent of the excitation wavelength. The large Stokes shift (129.5 nm), long PL lifetime (10.44 mu s), and huge Huang-Rhys factor (40.2) suggest that the blue PL originates from self-trapped excitons. After optimizing the reaction conditions and doping concentration, a high photoluminescence quantum yield of 86.98% is obtained. Moreover, the Mg-doped Cs2NaInCl6 DPs exhibit good resistance to irradiation and moisture, which are expected to remedy the shortage of current blue emitting materials.

Automated summary

Despite extensive efforts, there is still a high demand for lead-free, low toxicity, efficient, and stable blue fluorescent materials. Cs2NaInCl6 double perovskite (DP) is considered a promising candidate for solid-state lighting due to its low toxicity and good stability. Here, Mg-doped Cs2NaInCl6 DPs were prepared using a solvothermal method. The Mg2+-doped Cs2NaInCl6 DPs showed independent blue photoluminescence (PL) at 445 nm with a large Stokes shift (129.5 nm), long PL lifetime (10.44 μs), and a huge Huang-Rhys factor (40.2), indicating the presence of self-trapped excitons. After optimizing the reaction conditions and doping concentration, a high photoluminescence quantum yield of 86.98% was achieved. Moreover, the Mg-doped Cs2NaInCl6 DPs exhibited excellent resistance to irradiation and moisture, which can address the limitations of current blue emitting materials.