Porphyrin-functionalization of CsPbBrI$_{2}$/SiO$_{2}$ core-shell nanocrystals enhances the stability and efficiency in electroluminescent devices

TL;DR

This study demonstrates that porphyrin-functionalization of CsPbBrI$_{2}$/SiO$_{2}$ nanocrystals significantly improves their stability and electroluminescent efficiency by enhancing charge transfer and device performance.

Contribution

It introduces a novel ligand exchange method using porphyrins on inorganic perovskite nanocrystals, boosting stability and electroluminescent efficiency.

Findings

Enhanced current efficiency by 2-3 times due to lowered charging energy.

Achieved nearly fivefold increase in device efficiency with porphyrin ligands.

Verified strong ligand-nanocrystal interactions through spectroscopy and DFT calculations.

Abstract

Surface ligand exchange on all-inorganic perovskite nanocrystals of composition CsPbBrI$_{2}$ reveals improved optoelectronic properties due to strong interactions of the nanocrystal with mono-functionalized porphyrin derivatives. The interaction is verified experimentally with an array of spectroscopic measurements as well as computationally by exploiting density functional theory calculations. The enhanced current efficiency is attributed to a lowering of the charging energy by a factor of 2 to 3, which is determined by combining electronic and optical measurements on a selection of ligands. The coupled organic-inorganic nanostructures are successfully deployed in a light emitting device with higher current efficacy and improved charge carrier balance, magnifying the efficiency almost fivefold compared to the native ligand.