Ligand Engineering Enables Efficient Pure Red Tin-Based Perovskite Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Green Chemistry

Background:

• Tin (Sn)-based perovskite light-emitting diodes (PeLEDs) are promising eco-friendly alternatives to lead (Pb)-based devices.
• Challenges include poor film quality and Sn oxidation, limiting electroluminescence (EL) performance.
• Existing Sn-based PeLEDs lag behind Pb-based counterparts.

Purpose of the Study:

• To develop high-quality tin-based perovskite films for efficient pure red PeLEDs.
• To address issues of fast crystallization, Sn oxidation, and defect formation.
• To enhance the electroluminescence performance and stability of Sn-based PeLEDs.

Main Methods:

• Ligand engineering strategy using L-glutathione reduced (GSH) as surface ligands for phenethylammonium tin iodide (PEA2SnI4) films.
• Investigating hydrogen-bond and coordinate interactions between GSH and PEA2SnI4.
• Fabrication and characterization of PEA2SnI4-based PeLEDs.

Main Results:

• GSH effectively reduced perovskite crystallization rate and suppressed Sn2+ oxidation and defect formation.
• Improved PEA2SnI4 films exhibited excellent uniformity, density, coverage, optical properties, and stability.
• Achieved a record external quantum efficiency of 9.32% for PEA2SnI4-based pure red PeLEDs.

Conclusions:

• Ligand engineering with GSH is a feasible strategy to enhance Sn-based PeLED performance.
• This approach overcomes key limitations in tin-based perovskite materials.
• Demonstrates potential for high-performance, environmentally friendly display technologies.