New surface coating pathway by plasma-enabled surface-catalyzed reaction, offering control of surface chemistry, wettability and roughness.

Controlled modification of surfaces is one of the key pursuits of the nanoscience and nanotechnology fields. In article number 1903184, Kostya (Ken) Ostrikov and co‐workers from the Queensland University of Technology propose a concept which can enhance the capacity for the control of surfaces: plasma‐assisted nucleation and self‐assembly at atomic to nanoscales, scalable at atmospheric pressure.

the hole concentration in CuI 1−x Br x can be controlled by modifying the stoichiometric ratio of the halides, demonstrating that these binary halides are promising candidates for tailored electronic properties in next-generation devices. [8] In addition to the compositional variation, disorderrelated effects contribute to the changes in the electronic and optical structure in these solid solutions. [9] With these electronic applications in mind, the synthesis of CuX films has become a hot topic in recent years, with a focus on chemical vapor deposition [10][11][12] and vacuum deposition techniques such as molecular beam epitaxy, [13,14] reactive sputtering, [15] and thermal evaporation. [8,16,17] At the same time, the cuprous halides are promising candidates for other applications, such as the use of CuBr in sensing, [18][19][20] or the use of CuCl as cathode in Mg primary batteries. [21] The growth of CuX on copper is also of interest for batteries, as CuCl/ Cu anodes are being investigated for use in lithium ion batteries (LIBs), [21][22][23] and LIBs comprising an anode made from Cu foam covered with a CuBr-and Br-doped graphene-like film exhibit dendrite-free operation and an increased cycling stability. [24] This ever-expanding suite of applications means that it is of considerable interest to identify new approaches to CuX synthesis. One outstanding challenge is integrating CuX into composite films, where only a limited amount of work has been done. For example, a polyvinyl alcohol (PVA)/CuI composite material, in which the inorganic crystals were synthesized directly within the polymer matrix through the reduction of CuCl 2 by NaI in aqueous PVA solution, has shown promise for photovoltaic applications. [25] Similarly, a polypyrrole/CuI composite film synthesized through a one-pot approach, demonstrated electrochemical sensing properties. [26] Composite films comprising inorganic nanoparticles within a polymer matrix provide advantages for certain applications, where their contrasting and/or complementary properties can create synergistic benefits. [27] Here, we demonstrate a versatile, single-step approach to synthesizing an array of CuX composite films. The process involves deposition of a halogen-containing liquid organic precursor onto a metal substrate, and subsequent application of a dielectric barrier discharge (DBD) plasma. DBD plasma creates a reactive environment, in which electrons, ions, ultraviolet radiation, and free radicals can contribute to reactions in suitable precursor molecules. [28] We have previously shown that exposure to DBD plasma causes cleaving of the CCl bonds Cuprous halides (CuX) are transparent semiconductors with a range of appealing characteristics, and with targeted applications in electronics, energy storage, and sensing. Here, it is demonstrated that CuX films can be formed at room temperature and atmospheric pressure using a rapid, plasma-based approach. Crystalline CuX products are formed using dielectric barrier discharge plasma to react liquid small-molecule precu...

Recent advances in helium ion microscopy (HIM) have enabled the use of fine-focused He + beams to image and shape materials at the nanoscale. In addition to traditional ion milling, the beam can also be used to induce reactions, such as cross-linking, in films of organic molecules. Here, we compare the use of focused ion and electron beams to fabricate spatially-defined crosslinked features in nanometre-thick films of tetracene. Ion and electron beam treatments were performed using the focussed energetic beams in a HIM and a scanning electron microscope, respectively. The patterned samples were analysed by optical microscopy, HIM, atomic force microscopy and nanoindentation. For samples fabricated using both energetic beams, the total deposited particle dose could be used to modify the optical properties, thickness and hardness of the dosed regions. X-ray photoelectron spectroscopy revealed that the dosed regions exhibited a higher sp3 content, consistent with crosslinking; rinsing in solvent showed that the patterned regions were insoluble and could be isolated by removing the unmodified film through dissolution. These molecular nanopatterns demonstrate the promise for ultrahigh resolution chemical lithography, and for fabrication of nanocomponents with tailored physical properties.