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Electronic thin films play a ubiquitous role in microelectronic devices and especially hold great promise for flexible electronics, energy conversion and storage, and biomedical applications. Their characterizations, including ultra‐thin, large‐scale dimensions, stretchability, and conformal ability to curved or 3D structures, present new challenges for thin film fabrication based on the solution method. Electrospray deposition emerges as a feasible method for fabricating large‐area, flexible, and curved films. It offers many advantages such as material adaptability, controlled atomization, tunable film morphology, and shape retention on complex substrates. These advantages make it a key method for fabricating high‐performance films on large‐area, 3D surfaces. This work presents a comprehensive review of the mechanisms, processes, applications, and equipment of electrospray deposition. First, the fundamental principles of electrospray deposition are introduced, focusing on the mechanisms and scaling laws of liquid atomization. Moreover, the control methods for electrospray modes, structures, and film morphology are discussed. These advanced control methods pave the way for the fabrication of smart skins, wearable devices, and energy conversion and storage components. Finally, this work introduces three types of electrospray deposition manufacturing equipment to illustrate the advantages of electrospray deposition for large‐area, and 3D surface manufacturing. [ABSTRACT FROM AUTHOR]

Air cushioning and bubble entrapment are common phenomena observed during low-velocity droplet impact on solid or fluid surfaces, whereby a thin layer of air mediates the lubrication pressure. Previously, it is found that both charging droplets and the application of external electric fields can eliminate air cushioning and bubble entrapment. In this study, we numerically investigate the air cushioning and bubble entrapment in the charged droplet impacting onto a solid surface under external electric fields. It is found that the presence of net charge has a field enhancement effect on polarized charges on the same side while weakening the electric field of polarized charges on the opposite side, which can be linearly superimposed in the atmospheric environment. Based on the mirror charge model, the scaling law of the electric field threshold required for the impact of charged droplets without air cushioning or bubble entrapment is given. A fitting function based on the scaling law shows a good agreement with the phase diagram of a charged droplet impact modes under electric fields. These findings offer valuable insight for applications that rely on charged droplets' impact under electric fields, such as electrohydrodynamic printing and spray coating, to mitigate the negative impact of air cushioning or bubble entrapment. [ABSTRACT FROM AUTHOR]

Abstract Large amounts of amorphous silicon oxynitride nanowires have been synthesized on silicon wafer through carbon-assisted vapor-solid growth avoiding the contamination from metallic catalysts. These nanowires have the length of up to 100 μm, with a diameter ranging from 50 to 150 nm. Around 3-nm-sized nanostructures are observed to be homogeneously distributed within a nanowire cross-section matrix. The unique configuration might determine the growth of ternary amorphous structure and its special splitting behavior. Optical properties of the nanowires have also been investigated. The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance. These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle. Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.

We propose a novel technique of integrating silica nanowires to carbon microelectrode arrays on silicon substrates. The silica nanowires were grown on photoresist-derived three-dimensional carbon microelectrode arrays during carbonization of patterned photoresist in a tube furnace at 1000 °C under a gaseous environment of N2 and H2 in the presence of Cu catalyst, sputtered initially as a thin layer on the structure surface. Carbonization-assisted nucleation and growth are proposed to extend the Cu-catalyzed vapor–liquid–solid mechanism for the nanowire integration behaviour. The growth of silica nanowires exploits Si from the etched silicon substrate under the Cu particles. It is found that the thickness of the initial Cu coating layer plays an important role as catalyst on the morphology and on the amount of grown silica nanowires. These nanowires have lengths of up to 100 µm and diameters ranging from 50 to 200 nm, with 30 nm Cu film sputtered initially. The study also reveals that the nanowire-integrated microelectrodes significantly enhance the electrochemical performance compared to blank ones. A specific capacitance increase of over 13 times is demonstrated in the electrochemical experiment. The platform can be used to develop large-scale miniaturized devices and systems with increased efficiency for applications in electrochemical, biological and energy-related fields. [ABSTRACT FROM AUTHOR]

Abstract: Large quantities of single-crystal silicon oxynitride (SiOxNy) nanowires were synthesized on silicon substrate by a vapor–solid mechanism without using any catalyst. These single crystalline nanowires are 50 to 200nm in diameter, and a few hundreds of micrometers to several millimeters in length with high N concentration. The obtained SiOxNy nanowires are attractive by their exceptional whiteness, perceived brightness, and optical stability at high temperature. The experimental results show that the nanowire mat displays strong diffusive reflection over the whole visible wavelength, with more than 80% of light reflected at the wavelength range from 400 to 780nm. It is also demonstrated that the grown nanowires can be applied as coating material over reflector cup surface for white light-emitting diode lamp. It is shown that trapped modes can be significantly reduced by increasing the diffuse reflectivity of the reflector cup thus improving the lighting efficiency. [Copyright &y& Elsevier]