Hybrid Self-Assembled Molecules Reduce Interfacial Defects in Perovskite Light-Emitting Diodes

Self-assembled monolayers (SAMs) have exhibited widespread application in PeLEDs. However, most SAM molecules are amphiphilic, prone to forming micelles in solutions, which affects the uniformity of the film. In this work, we employed two SAM molecules to construct a hybrid SAM. By reducing the concentration of each component below the critical micelle concentration, the formation of micelles is inhibited. Additionally, the stability of mixed micelles was decreased through steric hindrance and hydrophobicity between different SAM molecules. SAM micelle formation is inhibited, resulting in more complete coverage of the buried interface. By utilization of this hybrid SAM, the thermally evaporated green PeLED achieved an EQE of 13.28%, representing advanced level performance in this field. Moreover, the devices maintained a high EQE of 8.30% at high current densities (@ 110 mA cm –2 ). This strategy offers a viable approach to circumvent the limitations associated with SAMs in PeLEDs, thereby enhancing their application potential.