Intense-pulsed-UV-converted perhydropolysilazane gate dielectrics for organic field-effect transistors and logic gates

Application of SiON Coatings in Sandstone Artifacts Conservation

For a long time, a large number of sandstone cultural relics have been exposed to the outdoors, and they are facing unprecedented threats. Curing perhydropolysilazane at varied pyrolysis times results in a series of SiON solids. Fourier transform infrared absorption spectroscopy (FTIR) results show that the Si−H bond disappears at 2163 cm−1, and that the Si−O peaks at 460 cm−1, becoming stronger during the pyrolysis of Perhydropolysilazane (PHPS) to SiON solids. X-ray photoelectron spectroscopy (XPS) results indicate a decrease in the proportion of N atoms from 22.71% to 3.38% and an increase in the proportion of O atoms from 59.74% to 69.1%, indicating a gradual production of SiO2 from perhydropolysilazane. To protect the sandstone, the SiON protective layer and the commonly used protective materials—acrylic resin and polydimethylsiloxane—are applied. When compared to sandstone treated with acrylic resin B72 and polydimethylsiloxane coatings, SiON-coated sandstone effectively reduces porosity and water absorption. Ageing tests have shown that the SiON-coated sandstone is effective in resisting crystalline damage from sodium sulfate. These thenardites can change shape during formation, allowing their widespread distribution in different locations in the sandstone. The surface thenardite of the SiON-treated samples was smaller than that of the polydimethylsiloxane and acrylic resin B72-treated samples, while the untreated samples were flaky with obvious dehydration characteristics.

Flexible Hard Coatings with Self-Evolution Behavior in a Low Earth Orbit Environment

Lightweight, long lifetime, and flexible polymer membrane-based structures, which are tightly folded on the ground and then unfolded in space, suffer from repeated bending before launching and fatal erosion on exposure to atomic oxygen (AO) in a low Earth orbit (LEO). Although various AO-resistant coatings have been developed, a coating that can simultaneously meet the critical requirements for the mechanical robustness and long-term protection of polymer membranes is rare. Here, we fabricated a coating with mechanical robustness and long-term space endurance, starting from an inorganic polymer precursor. A hybrid coating with a nanoscale polymer/silica bicontinuous phase is first prepared on the ground, which exhibits outstanding flexibility and excellent abrasion resistance. Then, the coating shows an in situ self-evolution behavior under AO and ultraviolet (UV) synergism to afford dense and crack-free silica coating with outstanding endurance. Our strategy displays great potential for protecting deployable membrane structures serving in the LEO.

Room-Temperature, Solution-Processed SiOx via Photochemistry Approach for Highly Flexible Resistive Switching Memory

Due to its high versatility and cost-effectiveness, solution process has a remarkable advantage over physical or chemical vapor deposition (PVD/CVD) methods in developing flexible resistive random-access memory (RRAM) devices. However, the reported solution-processed binary oxides, the most promising active layer materials for their compatibility with silicon-based semiconductor technology, commonly require high-temperature annealing (>145 °C) and the RRAMs based on them encounter insufficient flexibility. In this work, an amorphous and uniform SiO_x active layer was prepared by irradiating an inorganic polymer, perhydropolysilazane, with a vacuum ultraviolet of 172 nm at room temperature. The corresponding RRAM showed typical bipolar resistance switching with a forming-free behavior. The device on polyimide film exhibited outstanding flexibility with a minimum bending radius of 0.5 mm, and no performance degradation was observed after bending 2000 times with a radius of 2.3 mm, which is the best among the reported solution-processed binary oxide-based RRAMs and can even rival the performance of PVD/CVD-based devices. This room-temperature solution process and the afforded highly flexible RRAMs have vast prospects for application in smart wearable electronics.