All-solution-processed perovskite-quantum-dot light-emitting diodes through effective synergistic combination of orthogonal solvent and electron transport material

Perovskite quantum dots (PQDs) have shown great promise for use in photovoltaic devices, due to their ability to offer advantages such as tunability of visible light and efficient light emission. This study demonstrates the successful utilization of a triazine-based PO-T2T (2,4,6-Tris[3(diphenylphosphenyl)phenyl]-1,3,5-triazine; PO-T2T) as the electron transport layer (ETL) through an all-solution process. To improve the structural and optical characterization of CsPbBr3 and CsPbI3 QDs, three organic solvents, namely chlorobenzene, methyl acetate, and ethyl acetate, were selected to find an effective orthogonal solvent for PO-T2T. The all-solution processed devices incorporating PO-T2T and Methyl acetate (MeOAc) demonstrated impressive external quantum efficiencies of 5.57% for CsPbBr3 and 1.60% for CsPbI3 QDs. Notably, these devices also achieved the highest maximum luminance among all-solution processed PQDs-LEDs, with values of 33334 cd m–2 for CsPbBr3 and 224 cd m–2 for CsPbI3 QDs.