Heterodimensional Epitaxy of CsSnI₃ Microcrystalline Cubes for Bright and Efficient Near-Infrared Light-Emitting...

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• Tin-halide perovskites are promising for near-infrared (NIR) emission due to their eco-friendly nature, suitable bandgap, and rapid recombination.
• Challenges in tin perovskite films include easy Sn²⁺ oxidation and poor crystallization, leading to small grains and high defect concentrations, hindering efficient light emission.

Purpose of the Study:

• To develop a strategy for growing high-quality, single-crystalline tin-halide perovskite microstructures for efficient NIR emission.
• To address the issues of Sn²⁺ oxidation and defect density in tin perovskite films.

Main Methods:

• A surface-templated growth strategy was employed to create heterodimensional epitaxial cesium tin iodide (CsSnI₃) microcrystalline cubes.
• This method involved forming single-crystalline 3D domains with a 2D epitaxial passivation layer at the buried interface.

Main Results:

• The strategy effectively suppressed tin oxidation and minimized defect density in the CsSnI₃ microcrystals.
• The fabricated NIR Light-Emitting Diode (LED) demonstrated a high radiance of 152 W sr^-1 m^-2 and an external quantum efficiency (EQE) of 8.11%.

Conclusions:

• The developed surface-templated approach enables the fabrication of bright and efficient lead-free NIR light emitters.
• This work sets a new benchmark for tin-halide perovskite-based NIR LEDs, overcoming previous limitations.