Quantum-dot light-emitting diodes (QLEDs) combine the stable, efficient, and high color-purity emission of quantum dots (QDs) and the advantages of cost-effective solution-based processing techniques, promising large-area electroluminescent devices ideal

Solution-processed oxide thin films are actively pursued as hole-injection layers (HILs) in quantum-dot light-emitting diodes (QLEDs), aiming to improve operational stability. However, device performance is largely limited by inefficient hole injection at the interfaces of the oxide HILs and highionization-potential organic hole-transporting layers. Solution-processed NiO x films with a high and stable work function of ≈5.7 eV achieved by a simple and facile surface-modification strategy are presented. QLEDs based on the surface-modified NiO x HILs show driving voltages of 2.1 and 3.3 V to reach 1000 and 10 000 cd m −2 , respectively, both of which are the lowest among all solution-processed LEDs and vacuum-deposited OLEDs. The device exhibits a T 95 operational lifetime of ≈2500 h at an initial brightness of 1000 cd m −2 , meeting the commercialization requirements for display applications. The results highlight the potential of solution-processed oxide HILs for achieving efficient-driven and long-lifetime QLEDs.

Extensive efforts have been devoted to improving the operational performance of quantum-dot light-emitting diodes (QLEDs). However, the fundamental understanding of the relationship between the design of the hole-injection layer (HIL)/hole-transporting layer (HTL) interface and the operational stability of QLEDs is limited. Here, we demonstrate that in the operation of red QLEDs, the leakage electrons induce in situ electrochemical reduction reactions of the polyfluorene HTLs, which in consequence create trap states and deteriorate charge-transport properties. We invoke an oxygen-plasma treatment on the PEDOT:PSS HILs, resulting in HIL/HTL interfaces with enhanced hole-injection properties. This simple method leads to more efficient exciton generation in the QDs layer and mitigated leakage electron-induced degradation of the HTLs, enabling red-emitting QLEDs with improved operational performance, i.e., high external quantum efficiency of >20.0% at a brightness ranging from 1000 to 10 000 cd m–2 and a long T 95 operational lifetime of ∼4200 h at 1000 cd m–2.

Perovskite light-emitting diodes (PeLEDs) provide new opportunities for cost-effective and large-area electroluminescent devices. It is of interest to use ZnO-based electron-transport layers (ETLs), which demonstrate superior performance in other solution-processed LEDs, in PeLEDs. However, the notorious deprotonation reaction between ZnO and perovskite casts doubt on the long-term stability of PeLEDs with ZnO-based ETLs. This Perspective presents an overview of the chemical reactions that may occur at the interfaces between perovskite and ZnObased ETLs. We highlight that other interfacial reactions during the fabrication of PeLEDs, including the reactions between ZnO and the intermediate phase during perovskite crystallization and the amidation reactions catalyzed by ZnO, demonstrate critical utilities in the fabrication of high-efficiency and stable PeLEDs. Considering these recent advances, we propose future directions and prospects to design and control the interfacial reactions, aiming to fully exploit the potential of ZnO-based ETLs for realizing high-performance PeLEDs.

Delivery of CRISPR/Cas9 machineries into living cells and tissues is of paramount importance in a wide range of therapeutic applications, yet the shortage of delivery vectors that can efficiently deliver large CRISPR/Cas9 plasmids has severely impeded its applications from complicated and diverse genome-editing contexts. Herein, we demonstrate that cationic polymer-coated gold nanorods (AuNRs) with a high aspect ratio (AR) exhibit a unique manner to assemble DNA, excellent capability to mediate internalization, and strong ability to escape endosomes. The intracellular delivery mediated by cationic nanorods of a high AR enables Cas9-mediated genome editing and dCas9-mediated transcriptional activation, and in vivo delivery of CRISPR/Cas9 plasmid-targeting Fas by cationic AuNRs can successfully protect the mice from liver fibrosis. The current study reveals how nanomaterials with a particular structure contribute to genome-editing activity and defines a new method for the efficient delivery of CRISPR/Cas9 plasmids.