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In the context of the energy crisis, the optimal utilization of clean agricultural waste is of growing significance. This study employs a cost-effective method to obtain high-purity amorphous bio-based silica (RHA-SiO2) from rice husk ash (RHA) post pyrolysis. Leveraging the Taguchi method and response surface method (RSM) for the first time, this research utilizes pyrolysis and torrefaction temperatures as key determinants for the RHA-SiO2 particle size. Through an L36 (22 × 32) orthogonal test, key influencing factors were recognized. Subsequent optimization employed the central composite sequential (CCC) analysis, resulting in an interaction model that was experimentally validated with 96% to 99% accuracy. Such advanced techniques allow for a greater accuracy to be achieved in RHA-SiO2 extraction systems. [ABSTRACT FROM AUTHOR]

This work demonstrates a layer-by-layer etching technique to control the hexagonal boron nitride (h-BN) film thickness with single layer precision. The method involves top layer h-BN deformation via oxygen-radical adsorption and then top layer removal by nitrogen-ion bombardment. An ultimate monolayer h-BN with a smooth surface can be obtained from a thick flake by using the method repeatedly. The mechanism of the single layer h-BN etching is verified using X-ray photoelectron spectroscopy analysis and first principle molecular dynamics. Characterization of the dielectric properties of a thickness-reduced h-BN film shows a desirable low leakage current, large capacitance and high breakdown field properties as a gate dielectric material. [ABSTRACT FROM AUTHOR]

Besides its ubiquitous applications in optoelectronics, halide-perovskites (HPs) have also carved a niche in the domain of resistive switching memories (Re-RAMs). However owing to the material and electrical instability challenges faced by HP thin-films, rarely perovskite Re-RAMs are used to experimentally demonstrate data processing which is a fundamental requirement for neuromorphic applications. Here, for the first time, lead-free, ultrahigh density HP nanowire (NW) array Re-RAM has been utilized to demonstrate image processing via design of convolutional kernels. The devices exhibited superior switching characteristics including a high endurance of 5 × 10 6 cycles, an ultra-fast erasing and writing speed of 900 ps and 2 ns, respectively, and a retention time >5 × 10 4 s for the resistances. The work is bolstered by an in-depth mechanistic study and first-principles simulations which provide evidence of electrochemical metallization triggering the switching. Employing the robust multi-level switching behaviour, image processing functions of embossing, outlining and sharpening were successfully implemented.