Doped 0D Cs4PbCl6 single crystals featuring full-visible-region colorful luminescence

Abstract

To achieve colorful emissions spanning the full visible region is a fascinating target and remains full of challenge for metal ion doped 0D Cs₄PbX₆ perovskites. Herein, we succeed in obtaining four millimeter-scale Zr⁴⁺/Sn²⁺/Sb³⁺/Mn²⁺ doped 0D Cs₄PbCl₆ single crystals at the B-site by the hydrothermal method. Fascinatingly, these single crystals emit luminescence with blue, green, yellow and red colors, precisely covering the entire visible region. The homogeneous distribution of dopants in the single crystals is validated by optical microscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS) mapping. Four doped single crystals adopt two main emission mechanisms. The Mn²⁺-doped single crystal undergoes the free exciton–Mn²⁺ energy transfer process and then the spin-forbidden ⁴T_1g → ⁶A_1g transition of Mn²⁺. Other three doped single crystals adopt the luminescence kinetics via self-trapped excitons (STEs) associated with the dopants. Interestingly, Sb³⁺ and Sn²⁺ behave as both emitters and sensitizers. Moreover, we successfully tune the dopants’ ratio in Cs₄PbCl₆via two different methods, the hydrothermal synthesis and the precipitation synthesis. To date, this has been the first study that reports four luminescent doped 0D perovskite Cs₄PbCl₆ single crystals across the entire visible region. Furthermore, it is the first time to acquire a Zr⁴⁺-doped lead halide perovskite single crystal.