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Metal oxide thin‐film transistors (TFTs) offer remarkable opportunities for applications in emerging transparent and flexible microelectronics. Unfortunately, their performance is hindered by limitations associated with parasitic effects, such as parasitic electrode overlap capacitances and high contact resistance, which can severely limit their dynamic behavior. Here, an innovative method is reported to fabricate coplanar self‐aligned‐gate (SAG) indium‐gallium‐zinc‐oxide (IGZO) transistors with engineered source/drain contacts. The manufacturing process starts with the deposition and patterning of a gate electrode/dielectric stack and its functionalization with an organic self‐assembled monolayer (SAM) as the surface energy modifier. A second gold (Au) electrode is subsequently deposited over the gate electrode stack. The overlapping region between the two electrodes is removed via self‐delamination under mild sonication, forming perfectly aligned coplanar Au‐Gate‐Au electrodes. Device fabrication is completed with the spin coating of the IGZO precursor, followed by rapid photonic curing. Replacing the gold source/drain contact with bimetallic electrodes such as Au/In and Au/ITO enables a reduction in contact resistance and improves the transistor performance remarkably without increasing manufacturing complexity. The method is highly scalable, robust, and applicable to other semiconductor materials. [ABSTRACT FROM AUTHOR]

Chlorinated solvents are commonly used to process organic semiconductor devices but have several negative environmental impacts. The choice of processing solvent significantly affects the layer microstructure and device performance, so replacing chlorinated solvents is non-trivial. Herein, we investigate the microstructural and electron-transporting properties of small-molecule non-fullerene acceptor (NFA) films and transistors processed from various non-chlorinated solvents. We show that the ensuing NFA transistors exhibit improved layer morphology, crystallinity, and electron mobility superior to those processed from chlorinated solvents. Our work highlights using non-chlorinated solvents to optimise charge transport in organic semiconductors and their devices while mitigating adverse environmental effects. [ABSTRACT FROM AUTHOR]

Ferroelectric tunnel junctions (FTJs) are ideal resistance‐switching devices due to their deterministic behavior and operation at low voltages. However, FTJs have remained mostly as a scientific curiosity due to three critical issues: lack of rectification in their current‐voltage characteristic, small tunneling electroresistance (TER) effect, and absence of a straightforward lithography‐based device fabrication method that would allow for their mass production. Co‐planar FTJs that are fabricated using wafer‐scale adhesion lithography technique are demonstrated, and a bi‐stable rectifying behavior with colossal TER approaching 106% at room temperature is exhibited. The FTJs are based on poly(vinylidenefluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)], and employ asymmetric co‐planar metallic electrodes separated by <20 nm. The tunneling nature of the charge transport is corroborated using Simmons direct tunneling model. The present work is the first demonstration of functional FTJs manufactured via a scalable lithography‐based nano‐patterning technique and could pave the way to new and exciting memory device concepts. [ABSTRACT FROM AUTHOR]

Solution-processable poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is an important polymeric conductor used extensively in organic flexible, wearable, and stretchable optoelectronics. However, further enhancing its conductivity and long-term stability while maintaining its superb mechanical properties remains challenging. Here, a novel post-treatment approach to enhance the electrical properties and stability of sub-20-nm-thin PEDOT:PSS films processed from solution is introduced. The approach involves a sequential post-treatment with HNO 3 and CsCl, resulting in a remarkable enhancement of the electrical conductivity of PEDOT:PSS films to over 5500 S cm -1 , along with improved carrier mobility. The post-treated films exhibit remarkable air stability, retaining over 85% of their initial conductivity even after 270 days of storage. Various characterization techniques, including X-ray photoelectron spectroscopy, atomic force microscopy, Raman spectroscopy, Hall effect measurements, and grazing incidence wide angle X-ray scattering, coupled with density functional theory calculations, provide insights into the structural changes and interactions responsible for these improvements. To demonstrate the potential for practical applications, the ultrathin PEDOT:PSS films are connected to an inorganic light-emitting diode with a battery, showcasing their suitability as transparent electrodes. This work presents a promising approach for enhancing the electrical conductivity of PEDOT:PSS while offering a comprehensive understanding of the underlying mechanisms that can guide further advances., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Bismuth containing hybrid molecular ferroelectrics are receiving tremendous attention in recent years owing to their stable and non-toxic composition. However, these perovskite-like structures are primarily limited to ammonium cations. Herein, we report a new phosphonium based discrete perovskite-like hybrid ferroelectric with a formula [Me(Ph) 3 P] 3 [Bi 2 Br 9 ] (MTPBB) and its mechanical energy harvesting capability. The Polarization-Electric field (P-E) measurements resulted in a well-defined ferroelectric hysteresis loop with a remnant polarization value of 2.1 μC cm -2 . Piezoresponse force microscopy experiments enabled visualization of the ferroelectric domain structure and evaluation of the piezoelectric strain coefficient (d 33 ) for an MTPBB single crystal and thin film sample. Furthermore, flexible devices incorporating MTPBB in polydimethylsiloxane (PDMS) matrix at various concentrations were fabricated and explored for their mechanical energy harvesting properties. The champion device with 20 wt % of MTPBB in PDMS rendered a maximum peak-to-peak open-circuit voltage of 22.9 V and a maximum power density of 7 μW cm -2 at an optimal load of 4 MΩ. Moreover, the potential of MTPBB-based devices in low power electronics was demonstrated by storing the harvested energy in various electrolytic capacitors., (© 2022 Wiley-VCH GmbH.)