Highly Emissive Self-Trapped Excitons in Fully Inorganic Zero-Dimensional Tin Halides

Area of Science:

• Materials Science
• Solid-State Physics
• Photochemistry

Background:

• Achieving spatial localization of charge carriers is crucial for enhancing radiative recombination in luminescent semiconductors.
• Zero-dimensional (0D) materials inherently provide structural confinement, leading to localized Frenkel excitons.

Purpose of the Study:

• To introduce a novel 0D tin-based material, Cs4SnBr6, for efficient photoluminescence.
• To investigate the photoluminescent properties and potential for tuning emission in Cs4SnBr6 and its analogues.

Main Methods:

• Synthesis of the inorganic perovskite-derived 0D material Cs4SnBr6.
• Characterization of photoluminescence properties, including emission spectra and quantum yield.
• Preparation and analysis of a series of analogous compositions Cs4-xAxSn(Br1-yIy)6.

Main Results:

• Cs4SnBr6 exhibits room-temperature broad-band photoluminescence centered at 540 nm with a quantum yield of 15±5%.
• Analogous materials (Cs4-xAxSn(Br1-yIy)6) show tunable emission from 500 nm to 620 nm.
• Compositional tuning allows control over the Stokes shift and self-trapped exciton emission bands.

Conclusions:

• The 0D material Cs4SnBr6 is a promising candidate for efficient room-temperature photoluminescence.
• The developed materials offer tunable emission properties for potential applications in optoelectronics.
• Structural confinement in 0D materials effectively promotes exciton formation and radiative recombination.