摘要
Magnesium-doped zinc oxide (MZO) nanoparticles (NPs) with a cubic zinc blende (ZB) structure and with a hexagonal wurtzite (WZ) structure were prepared via a wet-chemical synthetic process by varying the base and used as the electron transport layer (ETL) for electroluminescent (EL) quantum-dot light-emitting diodes (QLEDs). Both as-synthesized MZO NPs were monodisperse with a polydispersity index <0.15 and retained excellent colloidal stability at least for 4 weeks. The formation of a NP film from the MZO NPs to configure the architecture of EL QLEDs resulted in significant enhancement in the charge carrier transport and the EL performance of QDs. It was found that the cubic MZO has more improvement than the hexagonal one on the EL device current density and current efficiency. Furthermore, considering the efficient recombination of electron and hole carrier transport, the conductive molecule tris(4-carbazoyl-9-ylphenyl)amine (TCTA) was added to poly(9-vinylcarbazole) (PVK) to increase the hole mobility. As a result, the EL QLEDs equipped with the combination of cubic MZO/TCTA-PVK carrier transport layers show 5-fold device efficiency and 10-fold brightness as high as 234,400 cd/m <sup>2</sup> , compared with conventional ZnO/PVK-based devices. This work highlights the potential of the cubic ZB-phase-based MZO film as the electron transport layer and TCTA mixed PVK in developing a solution for high-performance QLEDs.