Broadband red emission from one-dimensional hexamethonium lead bromide perovskitoid

Abstract

Broadband emissions from low-dimensional hybrid perovskites have aroused intense interest. However, the achievement of broadband red emission in lead halide perovskites remains challenging. Herein, we report a one-dimensional (1D) hybrid lead bromide perovskitoid, (HM)Pb₂Br₆ (HM = hexamethonium), featuring a corrugated “3 × 3” [Pb₂Br₆]²⁻ chain. The unique structure results in intriguingly red emission peaking at 692 nm, with a PLQY of around 6.24%. Our spectroscopic and computational studies reveal that the red emission derives from self-localized Pb₂³⁺, Pb³⁺ and Br₂⁻ species confined within the inorganic lead bromide lattice that function as radiative centres. This finding will benefit the design of perovskite systems for efficient red emission.