Transient currents induced by step voltage or polarity reversal of voltage applied to a liquid crystal cell containing a silicon substrate have been investigated. It is shown that the curves of transient current reveal a minimum for negative polarity of dc voltage relative to a silicon substrate of p-type conductivity. The time of the occurrence of the minimum corresponds to the collection of positive ions from the bulk of the liquid crystal at the silicon surface as a result of drift. This is explained by the formation of a highly resistive layer in the silicon under an electric field of positive ions collected at the silicon surface (a field effect). In polarity reversal experiments, a knowledge of the time of the occurrence of the minimum enables us to estimate the mobility of positive ions, which gives a value of 1.4 × 10(-11) M(2) Bc(-1).
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http://dx.doi.org/10.1088/0953-8984/20/27/275222 | DOI Listing |
Sci Rep
January 2025
Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, Xidian University, Xi'an, 710071, China.
(AlO)(HfO) films with varying compositions were deposited on silicon substrates via plasma-enhanced atomic layer deposition (PEALD), and metal-oxide-semiconductor (MOS) capacitors were fabricated. The impact of varying induced Al content on the dielectric properties of HfO was examined through electrical measurements. The results showed that increasing Al content raised the flat-band voltage, reduced the interface state density (D), and significantly lowered the leakage current at a given voltage.
View Article and Find Full Text PDFAnalyst
January 2025
The key Laboratory for Green Organic Synthesis and Application of Hunan Province, College of Chemistry, Xiangtan University, Xiangtan, 411105, China.
Developing low-cost self-service portable sensors to detect viruses is an important step in combating the spread of viral outbreaks. Here, we describe the development of an aptamer-free paper-based molecularly imprinted sensor for the instrument-free detection of influenza virus A (H5N1). In this sensor, Whatman paper loaded with FeO nanoparticles (WP@FeO) was prepared as a substrate upon which silicon imprinting occurred in the presence of the template virus H5N1.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Physics, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates.
Self-assembled gold nanoparticles (Au-NPs) possess distinctive properties that are highly desirable in diverse nanotechnological applications. This study meticulously explores the size-dependent behavior of Au-NPs under an electric field, specifically focusing on sizes ranging from 5 to 40 nm, and their subsequent assembly into 2D monolayers on an n-type silicon substrate. The primary objective is to refine the assembly process and augment the functional characteristics of the resultant nanostructures.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Beijing Key Lab for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China.
Optical computing offers advantages such as high bandwidth and low loss, playing a crucial role in signal processing, communication, and sensing applications. Traditional optical logic gates, based on nonlinear fibers and optical amplifiers, suffer from poor robustness and large footprints, hindering their on-chip integration. All-optical logic gates based on topological photonic crystals have emerged as a promising approach for developing robust and monolithic optical computing systems.
View Article and Find Full Text PDFMicromachines (Basel)
November 2024
Guangzhou Wide Bandgap Semiconductor Innovation Center, Guangzhou Institute of Technology, Xidian University, Guangzhou 510555, China.
In this work, we demonstrated the epitaxial growth of a gallium nitride (GaN) buffer structure on 200 mm SOI (silicon-on-insulator) substrates. This epitaxial layer is grown using a reversed stepped superlattice buffer (RSSL), which is composed of two superlattice (SL) layers with different Al component ratios stacked in reverse order. The upper layer, with a higher Al component ratio, introduces tensile stress instead of accumulative compressive stress and reduces the in situ curvature of the wafer, thereby achieving a well-controlled wafer bow ≤ ±50 µm for a 3.
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