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The effect of adding polyethylenimine (PEI) into the ZnO electron transport layer (ETL) of inverted quantum dot (QD) light emitting devices (QDLEDs) to form a blended ZnO:PEI ETL instead of using it in a separate layer in a bilayer ZnO/PEI ETL is investigated. Results show that while both ZnO/PEI bilayer ETL and ZnO:PEI blended ETL can improve device efficiency by more than 50% compared to QDLEDs with only ZnO, the ZnO:PEI ETL significantly improves device stability, leading to more than 10 times longer device lifetime. Investigations using devices with marking luminescent layers, electron-only devices and delayed electroluminescence measurements show that the ZnO:PEI ETL leads to a deeper penetration of electrons into the hole transport layer (HTL) of the QDLEDs. The results suggest that the stability enhancement may be due to a consequent reduction in hole accumulation at the QD/HTL interface. The findings show that ZnO:PEI ETLs can be used for enhancing both the efficiency and stability of QDLEDs. They also provide new insights into the importance of managing charge distribution in the charge transport layers for realizing high stability QDLEDs and new approaches to achieve that.
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http://dx.doi.org/10.1039/d1na00561h | DOI Listing |
ACS Appl Mater Interfaces
September 2025
Department of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Nanoionic devices, crucial for neuromorphic computing and ionically enabled functional actuators, are often kinetically limited. In bilayer configurations, experimentally deconvoluting ion transport within individual layers from the kinetics of transfer across solid-solid interfaces, however, remains a challenge, hindering rational device optimization. Here, we extend the dynamic current-voltage (-) technique to a PrCeO/LaCeCuO (PCO/LCCO) bilayer system, enabling the isolation and quantification of distinct ion transport processes.
View Article and Find Full Text PDFJ Phys Condens Matter
September 2025
Gunma University, 1-5-1 Tenjincho, Kiryu, 376-0052, JAPAN.
We review the fabrication and transport characterization of hexagonal boron nitride (hBN)/Bernal bilayer graphene (BLG) moiré superlattices. Due to the moiré effect, the hBN/BLG moiré superlattices exhibit an energy gap at the charge neutrality point (CNP) even in the absence of a perpendicular electric field. In BLG, the application of a perpendicular electric field tunes the energy gap at the CNP, which contrasts with single-layer graphene and is similar to the family of rhombohedral multilayer graphene.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2025
College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China. Electronic address:
Moisture-driven energy generators (MEGs) represent a renewable energy technology, yet challenges such as environmental humidity dependence and transient power generation behavior hinder their practical applications. Herein, a high-performance bilayer MEG is developed by integrating MXene-impregnated paper with a polyacrylamide (PAM) hydrogel to realize environmental tolerance and sustained power generation. Electronegative MXene and paper with 3D porous structure synergistically facilitate selective transport of positive charge, while the hydrogel serves as a water reservoir to provide a moist environment and migratory ions.
View Article and Find Full Text PDFPol Merkur Lekarski
September 2025
Kharkiv Clinical Hospital on Railway Transport No. 1 ≪Health Care Center≫ of Joint-Stock Company «Ukrainian Railways», Kharkiv, Ukraine.
Objective: Aim: The purpose was to identify the morphological features of the great saphenous vein in patients with chronic venous disease of the lower extremities undergoing treatment with endovenous high-frequency electric welding in automatic mode, endovenous laser ablation, and ultrasound-guided microfoam sclerotherapy.
Patients And Methods: Materials and Methods: The material for the comprehensive morphological study consisted of fragments of the great saphenous vein obtained from 32 patients with chronic venous disease of the lower extremities. The material was divided into three groups according to the endovenous treatment techniques applied.
Phys Rev Lett
August 2025
Gran Sasso Science Institute, The University of Edinburgh, School of Mathematics, Edinburgh EH93FD, United Kingdom and School of Mathematics, 67100 L'Aquila, Italy.
Multilayer networks provide a powerful framework for modeling complex systems that capture different types of interactions between the same set of entities across multiple layers. Core-periphery detection involves partitioning the nodes of a network into core nodes, which are highly connected across the network, and peripheral nodes, which are densely connected to the core but sparsely connected among themselves. In this paper, we propose a new model of core-periphery structure in multilayer networks and a nonlinear spectral method that simultaneously detects the corresponding core and periphery structures of both nodes and layers in weighted and directed multilayer networks.
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