High‐Performance Inverted Perovskite Quantum Dot Light‐Emitting Diodes Enabled by Dual Synergistic Interfacial Passivation

Inverted perovskite quantum dot light-emitting diodes (Pe-QLEDs) hold significant promise for next-generation displays due to their compatibility with n-type thin-film transistor-driven active-matrix panels, a critical advantage for industrial integration. However, interfacial reactions between the ZnO electron transport layer (ETL) and perovskite quantum dots (Pe-QDs) induce severe degradation and fluorescence quenching, undermining device efficiency and operational stability. To resolve this, we introduce a dual synergistic interfacial passivation strategy employing pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) as a multifunctional buffer layer. The PETMP layer addresses interfacial incompatibility through two synergistic mechanisms: (I) Thiol groups in PETMP form robust S─Zn bonds with the ZnO ETL, passivating surface oxygen vacancies, improving film morphology, and reducing the electron injection barrier. (II) Concurrently, these thiols coordinate with undercoordinated Pb ions on the Pe-QD surface, enhancing luminescence efficiency and suppressing non-radiative recombination. This dual synergistic passivation strategy yields inverted green Pe-QLEDs with a record maximum external quantum efficiency (EQE) of 24.35%, doubling the performance of conventional devices using polyvinyl pyrrolidone (PVP) buffers (EQE = 12.61%). Additionally, the optimized interface resulting from this strategy significantly enhances the operational stability of the devices. This work establishes PETMP-based passivation as a transformative approach for high-performance inverted Pe-QLEDs and other optoelectronic devices.