Aromatic ammonium salts ligand engineering-assisted CsPbBr3 quantum dots enable electroluminescent solar cell

All-inorganic perovskite quantum dots (QDs) have gained significant attention for their excellent optoelectronic properties, making them promising materials for applications in light-emitting diodes (LEDs) and solar cells (SCs), but it is still a challenge to balance colloidal stability of QDs and conductivity of QD films. To address the issue, an effective surface ligand engineering method has been employed by using phenethylammonium bromide (PEABr) to passivate the surface defects of QDs while enhancing the charge transport and injection in QD films. The results indicate that PEABr ligand has successfully been adsorbed onto the surface of CsPbBr3 QDs to passivate the vacancy defects, significantly enhance the electronic coupling between QDs. Systematically experimental studies show that PEABr post-treatment improves the PLQY (85 %) and stability of QDs with enhanced the carrier transport in QD film. Thanks to enhanced optoelectronic performance, the fabricated devices exhibited excellent photovoltaic (PV) and electroluminescent (EL) performance, and the CsPbBr3 QD SC had a PCE of 2.00 % while exhibiting a maximum luminance (Lmax) of 1512 cd cm-2, thus realizing highperformance electroluminescent solar cell.