The crucial role of nanocrystalline morphology in stabilizing the ferroelectric orthorhombic (o)-phase in doped-hafnia films is achieved via chemical solution deposition (CSD) by intentionally retaining carbonaceous impurities to inhibit grain growth. However, in the present study, large-grained (>100 nm) La-doped HfO (HLO) films are grown directly on silicon by adopting engineered water-diluted precursors with a minimum carbonaceous load and excellent shelf life. The o-phase stabilization is accomplished through a well-distributed La dopant, which generates uniformly populated oxygen vacancies, eliminating the need for oxygen-scavenging electrodes.
View Article and Find Full Text PDFThis study proposes the possibility of employing metal iodates as novel gas-sensing materials synthesized using a facile chemical precipitation method. An extensive survey of a library of metal iodates reveals that cobalt, nickel, and copper iodates are useful for gas sensor applications. Material analysis conducted using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravity differential temperature analysis, and Raman spectroscopy enables us to understand the thermal behavior and optimize post-annealing conditions.
View Article and Find Full Text PDFTransition-metal dichalcogenides possess high carrier mobility and can be scaled to sub-nanometer dimensions, making them viable alternative to Si electronics. WSe is capable of hole and electron carrier transport, making it a key component in CMOS logic circuits. However, since the p-type electrical performance of the WSe-field effect transistor (FET) is still limited, various approaches are being investigated to circumvent this issue.
View Article and Find Full Text PDFThe technological ability to detect a wide spectrum range of illuminated visible-to-NIR is substantially improved for an amorphous metal oxide semiconductor, indium gallium zinc oxide (IGZO), without employing an additional photoabsorber. The fundamentally tuned morphology via structural engineering results in the creation of nanopores throughout the entire thickness of ∼30 nm. See-through nanopores have edge functionalization with vacancies, which leads to a large density of substates near the conduction band minima and valence band maxima.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2021
Ultralow-power logic devices are next-generation electronics in which their maximum efficacies are realized at minimum input power expenses. The integration of ferroelectric negative capacitors in the regular gate stacks of two-dimensional field-effect transistors addresses two intriguing challenges in today's electronics; short channel effects and high operating voltages. The complementary-metal-oxide-semiconductor-compatible HfZrO (HZO) is an excellent ferroelectric material crystallized in a noncentrosymmetric o-phase.
View Article and Find Full Text PDFNeuromorphic engineering, a methodology for emulating synaptic functions or neural systems, has attracted tremendous attention for achieving next-generation artificial intelligence technologies in the field of electronics and photonics. However, to emulate human visual memory, an active pixel sensor array for neuromorphic photonics has yet to be demonstrated, even though it can implement an artificial neuron array in hardware because individual pixels can act as artificial neurons. Here, we present a neuromorphic active pixel image sensor array (NAPISA) chip based on an amorphous oxide semiconductor heterostructure, emulating the human visual memory.
View Article and Find Full Text PDFWater sensors are a type of level sensor that can be used in various applications requiring the sensing of water levels, such as in dams, nuclear power plants, water pipes, water tanks, and dehumidifiers. In particular, water sensors in water ingress monitoring systems (WIMS) protect lives and property from disasters caused by water leakage and flooding. Here, a resistive water sensor for WIMS that incorporates poly(3,4-ethylenedioxythinophene):poly(styrene sulfonate) (PEDOT:PSS) grafted with poly(ethylene glycol) methyl ether (PEGME) (PEDOT:PSS--PEGME copolymer) as high-conductivity electrodes and laser-treated PEDOT:PSS--PEGME copolymer as the low-conductivity resistive component is reported.
View Article and Find Full Text PDFObjectives: The use of indium compounds, especially those of small size, for the production of semiconductors, liquid-crystal panels, etc., has increased recently. However, the role of particle size or the chemical composition of indium compounds in their toxicity and distribution in the body has not been sufficiently investigated.
View Article and Find Full Text PDFObjectives: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats.
Methods: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'.
Objectives: We sought to establish a novel method to generate nano-sized carbon black particles (nano-CBPs) with an average size smaller than 100 nm for examining the inhalation exposure risks of experimental rats. We also tested the effect of nano-CBPs on the pulmonary and circulatory systems.
Methods: We used chemical vapor deposition (CVD) without the addition of any additives to generate nano-CBPs with a particle size (electrical mobility diameter) of less than 100nm to examine the effects of inhalation exposure.
Food Chem Toxicol
September 2009
The subchronic toxicity of sec-butanethiol was investigated in Sprague-Dawley rats following a 13-week period of repeated inhalation exposure. Four groups of 10 rats of each sex were exposed to sec-butanethiol vapor by whole-body inhalation at 0, 25, 100, or 400 ppm for 6 h per day, 5 days a week over a 13-week period. At 400 ppm, both genders exhibited a decrease in food consumption, although a decrease in the body weight gain was only observed in females.
View Article and Find Full Text PDF