Charge Transport between Coupling Colloidal Perovskite Quantum Dots Assisted by Functional Conjugated Ligands

Long alkyl‐chain capping ligands are indispensable for preparing stable colloidal quantum dots. However, its insulating feature blocks efficient carrier transport among QDs, leading to inferior performance in light‐emitting diodes (LEDs). The trade‐off between conductivity and colloidal stability of QDs has now been overcome. Methylamine lead bromide (MAPbBr3) QDs with a conjugated alkyl‐amine, 3‐phenyl‐2‐propen‐1‐amine (PPA), as ligands were prepared. Owing to electron cloud overlapping and the delocalization effect of conjugated molecules, the conductivity and carrier mobility of PPA‐QDs films increased almost 22 times over that of OA‐QD films without compromising colloidal stability and photoluminescence. PPA‐QDs LEDs exhibit a maximum current efficiency of 9.08 cd A−1, which is 8 times of that of OA‐QDs LEDs (1.14 cd A−1). This work provides critical solution for the poor conductivity of QDs in applications of energy‐related devices.