Interfacial Molecular Engineering for Efficient Sn Perovskite Light-Emitting Diodes

In recent years, perovskite light-emitting diodes (PeLEDs) have demonstrated exceptional potential, achieving high external quantum efficiencies (EQEs) exceeding 20%. However, these advancements have primarily focused on visible colors, and toxic elements such as Pb are used in these devices. Tin (Sn) perovskites with a narrow band gap of nearly 1.3 eV present a promising candidate for lead-free near-infrared PeLEDs. Nonetheless, Sn oxidation and high defect density from fast crystallization are still hurdles to overcome. This study investigates the impact of a newly synthesized ethylenedioxythiophene (EDOT)-based conjugated organic ligand on Sn-based PeLEDs, aiming to enhance device performance by reducing the defect density and Sn oxidation. The EDOT-treated PeLED device achieves a high EQE of 6.4% and exhibits stable electroluminescence spectra, demonstrating the potential of ligand treatments in optimizing Sn-based PeLEDs.