A One-Dimensional Organic Lead Chloride Hybrid with Excitation-Dependent Broadband Emissions

Organic–inorganic
metal halide hybrids have emerged as a
new class of materials with fascinating optical and electronic properties.
The exceptional structure tunability has enabled the development of
materials with various dimensionalities at the molecular level, from
three-dimensional (3D) to 2D, 1D, and 0D. Here, we report a new 1D
lead chloride hybrid, C4N2H14PbCl4, which exhibits unusual inverse excitation-dependent broadband
emission from bluish-green to yellow. Density functional theory calculations
were performed to better understand the mechanism of this excitation-dependent
broadband emission. This 1D hybrid material is found to have two emission
centers, corresponding to the self-trapped excitons (STEs) and vacancy-bound
excitons. The excitation-dependent emission is due to different populations
of these two types of excitons generated at different excitation wavelengths.
This work shows the rich chemistry and physics of organic–inorganic
metal halide hybrids and paves the way to achieving novel light emitters
with excitation-dependent broadband emissions at room temperature.