Efficient and stable perovskite electrochemiluminescence based on low-resistance, efficient and stable CsPbX3 (X = Cl, Br, I) perovskite quantum dots.

Perovskite quantum dots (PQDs) show great potential for optoelectronic devices, but their application in electrochemical systems is hindered by the insulating nature of conventional long-chain ligands (e.g., oleic acid/oleylamine). We introduce a short-chain post-treatment strategy to efficiently reduce the capping density of these ligands in CsPbX3 (X = Cl, Br, I) PQDs. Through DFT calculations, FTIR, XPS, and photoluminescence studies, we elucidate the molecular mechanisms of ligand exchange and its impact on electrochemical performance. In situ electrochemical Raman and electrochemiluminescence (ECL) experiments demonstrate that the treated PQDs exhibit enhanced conductivity, environmental stability, and quantum efficiency, with ECL efficiency and operational stability significantly surpassing those of pristine OA/OAM-capped PQDs. This work establishes a generalizable ligand design paradigm that optimizes PQD conductivity, stability, and quantum efficiency simultaneously, providing a critical breakthrough for next-generation electrochemical PQD technologies.