Near-unity photoluminescence quantum yield in zero-dimensional lead-free indium-based hybrid perovskites by antimony doping

Abstract

Lead-free zero-dimensional (0D) hybrid halide perovskites have recently attracted considerable attention due to their outstanding photophysical properties. Although broadband emission can be obtained in metal halide perovskites, the realization of highly efficient light emission with a near-unity photoluminescence quantum yield (PLQY) remains extremely challenging. In this study, lead-free (C₄H₁₂N)₂InCl₅·DMF (DMF = HCON(CH₃)₂) crystals with a 0D structure were investigated as a pristine compound to design novel luminescent materials, which enables broadband yellow emission with high PLQY up to 99.3% via Sb³⁺-doping. Steady-/transient-state spectral analysis reveals that the broadband emission originates from self-trapped excitons of the Sb³⁺ luminescent center. High PLQY and excellent environmental stability pave the way for its further applications in light-emitting diodes. The results provide fundamental insight into the efficient light emission of Sb³⁺ in hybrid metal halides and offer guidance for the design of promising luminescent materials for optoelectronic applications.