Drag force shear manipulating ligand distribution at perovskite buried interface enables efficiently suppressed EQE roll-off of perovskite light-emitting diodes

• Published in: Nano energy 2024-08, Vol.127, p.109797, Article 109797
• Main Authors: Wang, Qungui, Peng, Xiaodong, Li, Wen, Zeng, Xiankan, Chen, Yongjian, Pan, Lunyao, Tang, Guanqi, Chen, Xiangrong, Yang, Weiqing
• Format: Article
• Language: English
• Subjects: Buried interface; Drag force shear; Ligand distribution; Nanocrystals; Perovskite light-emitting diode
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2024.109797

Effectively manipulating the ligand distribution at the perovskite buried interface is critical for achieving high-performance nanocrystal-based perovskite light-emitting diodes (PeLEDs). However, it is challenging to realize it due to the non-exposed feature of the buried interface. Here, the drag force shear (DFS) is utilized to successfully regulate the ligand distribution at the perovskite buried interface which can effectively suppress the EQE roll-off of devices. By manipulating the ligand distribution at the perovskite buried interface, it is revealed that a more ligand preservation could result in an improved defect passivation leading to higher EQE, while the carrier injection barrier is increased simultaneously making devices suffer from severe EQE roll-off and decreased luminance, and vice versa. With the help of optimizing the ligand distribution by manipulating the DFS, the balance between carrier injection and interfacial defect passivation is successfully achieved. Resultantly, an enhanced EQE of 17.24 % with substantially suppressed EQE roll-off is reached, culminating in a remarkable luminance of 61,900 cd/m2. This work presents an efficient approach to control ligand distribution at the perovskite buried interface and offers valuable insights for realizing high luminance and low EQE roll-off of PeLEDs. [Display omitted] •By peeling-off and exposing buried interface, we revealed that drag force shear (DFS) can manipulate the ligand distribution.•Decreasing DFS enriches ligand distribution, leading to better defect passivation but a higher electrical injection barrier.•Increasing DFS reduces ligand distribution, leads to a lower electrical injection barrier but also more the defects.•The electrically injection barrier and defect passivation at buried interface are balanced by optimizing the DFS.•The EQE roll-off of optimized PeLED is evidently suppressed, leading to an EQE of 17.25 % and 4.5 times higher of luminance.