High-Performance Inverted Perovskite Quantum Dot Light-Emitting Diodes Enabled by Dual Synergistic Interfacial
Shuai Liu1, Xiansheng Li1, Changting Wei1
1Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
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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.
