Mohd Rezeq

• Professor (Associate) at Khalifa University

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...

This research reports a continuous output ionic thermoelectric (i‐TE) system based on MXene/PVA (polyvinyl alcohol) hydrogel, by utilizing thermo‐diffusion of Cu²⁺ and Cl⁻ ions and the redox reaction involving Cu/Cu²⁺ at the electrode interfaces. The thermopower of the i‐TE system can be independently tuned to a value of −3.13 mVK⁻¹ by adjusting th...

Energy harvesting from ambient sources present in the environment is essential to replace traditional energy sources. These strategies can diversify the energy sources, reduce maintenance, lower costs, and provide near-perpetual operation of the devices. In this work, a triboelectric nanogenerator (TENG) based on silane-coupled Linde type A/ polydi...

A noble metallenes family-2D Goldene (Au-ene)/monolayers of gold nanoparticles (Au- NPs) have garnered significant attention due to their unique physicochemical properties, which are instrumental in various technological applications. This review...

Flexible thermoelectric composites are promising in harvesting low‐temperature energies and have a wide range of applications in wearable devices. However, the uncontrollable interfaces between the components significantly scatter the transport of electrons leading to a reduced thermoelectric performance. In this research, hydrochloride acid doped...

The rapid and efficient sensing mechanism of molecules and bimolecular species is crucial for healthcare, biomedical, and safety applications. Such sensors need to be robust and able to measure low concentrations of molecular species. Utilizing the intriguing effect of the enhanced electric field from charged gold nanoparticles (Au‐NPs), due to the...

Correction for ‘Physical probing of quantum energy levels in a single indium arsenide (InAs) quantum dot’ by Moh'd Rezeq et al. , Nanoscale Adv. , 2023, 5 , 5562–5569, https://doi.org/10.1039/D3NA00638G.

Advances in materials science and memory devices work in tandem for the evolution of Artificial Intelligence systems. Energy-efficient computation is the ultimate goal of emerging memristor technology, in which the storage and computation can be done in the same memory crossbar. In this work, an analog memristor device is fabricated utilizing the u...

Nanoparticles (NPs) bridge the gap between bulk materials and their equivalent molecular/atomic counterparts. The physical, optical, and electronic properties of individual NPs alter with the changes in their surrounding environment at the nanoscale. Similarly, the characteristics of thin films of NPs depend on their lateral and volumetric densitie...

Indium arsenide (InAs) quantum dots (QDs) grown by molecular beam epitaxy (EBM) on gallium arsenide (GaAs) substrates have exhibited quantized charge-trapping characteristics. An electric charge can be injected in a single QD by a gold-coated AFM nano-probe placed directly on it using a conductive-mode atomic force microscope (C-AFM). The results r...

This study presents a method to enhance data processing by integrating a unidirectional analogue artificial neuromorphic memristor device with a piezoelectric nanogenerator, taking inspiration from biological information processing. A self-powered unidirectional neuromorphic resistive memory device is proposed, comprising an ITO/ZnO/Yb 2 O 3 /Au st...

Dynamic control of a material's thermal emission could enable many emerging applications, such as thermal camouflage and infrared (IR) display. Low-dimensional carbon nanomaterials have shown great potential in these applications because of their tuneability in charge density via static gating or ionic intercalation. Herein, a thermal emission modu...

Due to their stability, single-walled carbon nanotubes (SWCNTs) have been used for multiple applications in the semiconductor industry. Herein, we report the humidity sensing capability of SWCNTs by comparing the different densities of SWCNTs dispersed on the sensing area of the planner sensor device. Three different humidity sensors have been fabr...

This work reports a high-performance, low-cost, biocompatible triboelectric nanogenerator (TENG)using chicken skin (CS). The device is suitable to power wearable devices, which is critical to adaptelectronics in monitoring, predicting, and treating people. It also supports sustainability by providinga cost-effective way to reduce the poultry indust...

Environmentally friendly humidity sensors with high sensing performance are considered crucial components for various wearable electronic devices. We developed a rapid-response and durable Paper Cellulose Fiber/Graphene Oxide Matrix (PCFGOM) humidity sensor using an all-carbon functional material. The fabricated sensor demonstrated a high sensitivi...

This article focuses on the development of triboelectric nanogenerator (TENG) by utilizing advanced 2D nanoma-terials with innovative design and easy fabrication method to achieve durable TENG with high-power density and improved cycling performance. Herein, we fabricated a layer-by-layer stacked vertical contact-separation (CS) mode TENG. In this...

Recently, phase change chalcogenides, such as monochalcogenides, are reported as switching materials for conduction‐bridge‐based memristors. However, the switching mechanism focused on the formation and rupture of an Ag filament during the SET and RESET, neglecting the contributions of the phase change phenomenon and the distribution and re‐distrib...

The optical rectenna is a device that converts the optical range of electromagnetic radiations to a direct current. Optical antennas, as for the radio frequency (RF) antennas, require an antenna’s structure in the range of optical light EM wavelengths, i.e., a few hundred nanometers to a few micrometers. Herein, we demonstrate the optical rectenna...

Herein, a cobalt borate (CoBi) based synaptic device (nano-memristor) was fabricated via solution process electrochemical deposition technique, in which equally spaced nanocrystalline cobalt oxide particles were embedded in an amorphous borate (B-O) mesh. The synaptic properties across the fabricated film were investigated with the help of conducti...

Indium arsenide (InAs) quantum dots (QDs) have been characterized using a conductive-mode atomic force microscope (C-AFM), where a well-defined gold-coated AFM probe has been used to electrically probe each individual QD. The InAs QDs were grown on a gallium arsenide (GaAs) substrate in a self-assembled manner by using molecular beam epitaxy (MBE)....

To optimize the performance of carbon nanotube (CNT)-based rectennas, we have studied the effect of metal work function on the photodetection characteristics. Two materials of conducting nanoprobes, namely, gold (Au) and platinum (Pt), have been used to form a rectifying diode at the interface with the CNT. The electrical and optical characteristic...

We present an optical rectenna by engineering a rectifying diode at the interface between a metal probe of an atomic force microscope (AFM) and a single wall carbon nanotube (SWCNT) that acts as a nano-antenna. Individual SWCNT electrical and optical characteristics have been investigated using a conductive AFM nano-probe in contact with two device...

In this work, we investigate the time dependence of trapped charge in isolated gold nanoparticles (Au-NPS) dispersed on n-Si substrates, based on the electrical characteristics of nano metal–semiconductor junctions. The current–voltage (I–V) characteristics have been analysed on a single Au-NP at different time intervals, using conductive mode atom...

We demonstrate a metal-oxide-semiconductor based nonvolatile memory element structure with a single isolated gold nanoparticle (Au-NP) acting as the storage site. The Au-NPs are sandwiched between amorphous Al2O3 thin films, deposited using the atomic layer deposition method to form the blocking and tunneling layers. The current voltage characteris...

Improving Schottky diode characteristics in semiconducting devices is essential for better functionality in electronic and optoelectronic devices. In this paper we investigate the electric transport characteristics of a gold (Au)-tip/n-Si based nano Schottky diode by using the conductive mode of the atomic force microscope (C-AFM). 10 nm average di...

Silicon (Si)-based photodetectors are appealing candidates due to their low cost and compatibility with the complementary metal oxide semiconductor (CMOS) technology. The nanoscale devices based on Si can contribute efficiently in the field of photodetectors. In this report, we investigate the photodetection capability of nano-Schottky junctions us...

Electrostatic properties at the nanoscale under relevant environment is of potential use in novel electrical and optical applications that bulk materials and devices can’t provide. For instance, Nanoparticles (NPs) based structures have drawn a lot of attention for possible memory-based applications. Embedding different kind of NPs in thin dielectr...

We have studied the dependence of Schottky junction (I–V) characteristics on the metal contact size in metal–semiconductor (M–S) junctions using different metal nanoprobe sizes. The results show strong dependence of (I–V) characteristics on the nanoprobe size when it is in contact with a semiconductor substrate. The results show the evolution from...

The rapid advance in microscopy in the last few decades enabled researchers to fabricate, manipulate and characterize materials at nano-scale. The fabrication of ultra-sharp tips with an apex of few nanometers (referred to as nanotips) and single atom tips (SATs) considerably optimizes the image resolution of scanning probe microscopes and electron...

Formation of metal-semiconductor (M-S) contacts at sub-20 nanometer range is a key requirement for down-scaling of semiconductor devices. However, electrical measurements of M-S contacts at this scale have exhibited dramatic change in the current-voltage (I-V) characteristics compared to that of conventional (or planar) Schottky contacts. This chan...

Nanotips are considered significant elements in some of nanotechnology instruments. They are used in scanning probe microscopes and electron microscopes to characterize materials at the nano and atomic scales. Therefore, the size and profile of the nanotip determines the performance of these microscopes. The advancement of nanotip fabrication techn...

Nano metal-semiconductor contacts in sub 20 nm range have shown a deviation in the electrical characteristics compared to conventional diodes. We have used a finite element simulation software to build and analyze a proposed geometrical model. We used two different theoretical approaches to study the enhancements of the electric field at the interf...

Nanotips have attracted increasing interest in several aspects of nanotechnology, particularly in nanotip-based microscopy and nano-characterization. Therefore, fabricating nanotips with well-defined shapes and in a highly controlled process is vital for these applications. Here, we present some characterization analysis of nanotips fabricated by t...

Nanotips have attracted increasing interest in several aspects of nanotechnology, particularly in nanotip based microscopy and nano-characterization. Therefore, fabricating nanotips with well-defined shapes and in a highly controllable way is vital. Here we present some characterization analysis of nanotips prepared by the recently developed local...

Nano metal-semiconductor contacts in sub-20 nm range have showed unusual electrical characteristics compared to conventional diodes. New devices based on nano Schottky junction have been proposed to overcome the limitations of CMOS devices. Here we introduce a new theoretical approach for studying the enhancement of the electric field at the interf...

A new method for fabricating nano ion-electron sources and nano probes with an apex in the range of 1 nm is introduced. The method is based on bombarding a regular tip apex with electrons extracted and accelerated from a nearby source by the electric field. This can be achieved by placing a metal ring around a precursor metal tip at a level below t...

Due to their crucial applications in nanotechnology, several methods have been developed for fabricating nanotips. Such nanotips can be fabricated and characterized in the field ion microscope (FIM), and can be tapered down to a single atom apex. As only a top view of the tip apex can be captured and analyzed in the FIM the overall nanotip shape is...

There is an increasing interest in reducing the size of semiconductor devices to sub 20 nm scale for achieving low power consumption and attaining high switching speed. Electronic device based on nano Schottky junctions have the potential to address these issues due to interesting interface characteristics that deviate from the conventional Schottk...

As technology is growing very fast reaching every single human activity, the interest increases about having a faster performance and less power consumption in smaller size electronic devices. Consequently, many research efforts focus on further the size reduction of electronic devices. This size reduction is needed to allow multiple applications o...

Nanotips continue to be of crucial importance to Electron Microscopes, the sharpness of such nanotips plays a vital role in producing coherent electron and ion beams and hence improving the scanning resolution of these microscopes. Thus, a lot of research is being conducted to fabricate the ultimate sharp tip using Field Emission Microscope (FEM) a...

Using a field emission microscope (FEM), the first image ever of isolated individual molecules was reported in the 1950s. At that time, the Cu-Phthalocyanine (Cu-Pc) molecule was imaged in different configurations, namely two- and four-leaf patterns. These various apparent shapes were linked to the location of the molecule on particular atomic plan...

Reducing the size of metal-semiconductor (M-S) contacts to sub 20 nm results in a deviation of the interface barrier characteristics from the those predicted by the conventional theory of (M-S) contacts. This is attributed to the enhancement of the electric field at the interface due to the charge confinement in the nano metal particle. We introduc...

Nanotips with a single atom end have proven to be ideal sources for self collimated electron and ion beams, which presents them as vital tools for ion and electron microscopy. The sharpness of such nanotips is usually inferred from the highly focused ion and electron single spots in the field ion microscope (FIM) and the field emission microscope (...

Reduced metal-semiconductor contacts to sub 10 nm range have exhibited interesting characteristics that drastically deviate from those related to planar Schottky contacts. We present a theoretical model with analytical analyses that describe the crucial effect of the size of the metal contact, with a semiconductor substrate, on the energy band stru...

Nanotips are highly demanded for various applications in nanotechnology. For instance, nanotips with a single atom end can be used as a source of self collimated electron or ion beams. Such tips are usually characterized in the field ion microscope (FIM) or the field emission microscope (FEM), where only a top view can be captured and analyzed. We...

Nanotips are the main components in most of the powerful nanotechnology tools like scanning tunneling microscope (STM) and scanning transmission electron microscope (TEM). Therefore the improvement of the performance of these microscopes relies on fabricating extremely sharp tips with well defined shapes. Tips with an apex radius of a few nanometer...

Nanotips have been in increasing demand over the last two decades, owing to their crucial role in the main nanotechnology instruments, like scanning probe microscopes and scanning electron and transmission microscopes. Well-defined ultrasharp tips have also attracted a growing interest in molecular electronics, as they are needed for fabrication an...

The scientific and technical challenges involved in building the planar electrical connection of an atomic scale circuit to N electrodes (N > 2) are discussed. The practical, laboratory scale approach explored today to assemble a multi-access atomic scale precision interconnection machine is presented. Depending on the surface electronic properties...

Several workers have reported on the observation of a peak, in the magnetic flux trapped by polycrystalline type II superconductors, when plotted versus the cooling fields from TC, and versus the magnitude of the half-cycle fields applied after zero-field cooling. We report on our observations of this behavior in a niobium sample and present a deta...

Nanotip technology is increasingly demanded for molecular and atomic characterizations and manipulations. Restoration of the atomic structure of the tip apex in situ is a crucial factor in this work. We demonstrate the modification of the apex structure with atomic precision down to a single atom and introduce a new approach for modelling the arran...

The spatially controlled field assisted etching method for sharpening metallic tips, in a field ion microscope (FIM), is used to study the evolution of the field emission when the tip apex radius is decreased below 1nm. Unlike the conventional image formation in a field emission microscope (FEM), we demonstrate that at this scale the field emission...

Well defined and ultra-sharp tips are highly demanded in scanning probe microscopy for acquiring atomic resolution as well as for the manipulation and characterization of molecules and nano-structures. There is also an increasing interest in developing electron beam sources with a high brightness and coherency as these factors have a direct impact...

Altshuler et al discovered that dICO/dlnt, the rate of increase of the critical current IC with time in polycrystalline high TC samples, traced a peak when measured versus HM, the amplitude of the sweep of the flux trapping magnetic field. We show that the sharp peak in dICO/dlnt which their model generates arises from a special feature of the form...

In this report we present a straightforward new technique for fabricating nanotips. This approach is based on spatially controlling the reaction of nitrogen gas with the surface atoms of a tungsten tip in a field ion microscope (FIM). Confining this field-assisted etching reaction to the shank has enabled us to produce single-atom tips with an apex...

Electrical transport through molecules has been much studied since it was proposed that individual molecules might behave like basic electronic devices, and intriguing single-molecule electronic effects have been demonstrated. But because transport properties are sensitive to structural variations on the atomic scale, further progress calls for det...

In the analysis of Ic hysteresis phenomena, many researchers have assumed that the return field Hr(Ha,T) obeys a linear relationship, Hr=CMg(Ha,T) where C is a parameter of the specimen which may depend on T, and Mg is the magnetization of the grains. Kwasnitza and Widmer [IEEE Trans. Magn. 27 (1991) 1202] measured both Ic and Mg at a chosen temper...

In the analysis of Ic hysteresis phenomena, many researchers have assumed that the return field Hr(Ha,T) obeys a linear relationship, Hr=CMg(Ha,T) where C is a parameter of the specimen which may depend on T, and Mg is the magnetization of the grains. Kwasnitza and Widmer [IEEE Trans. Magn. 27 (1991) 1202] measured both Ic and Mg at a chosen temper...

The established model, which accounts for the magnetothermal behaviour of isotropic type II superconductors during slow cooling and warming below Tc in a static magnetic field, is extended to reproduce the observations of Hyun [Phys. Rev. B 48 (1993) 1244] of the enhancement of the magnitude of the diamagnetic magnetization Mg of Nb3Sn single cryst...

Several workers have observed that, after fast field cooling of weak-linked granular high Tc type II superconductors, the diamagnetic magnetization will increase and trace a valley, hence a peak of enhanced Meissner effect, as the temperature approaches Tc during slow warming to the normal state with the applied field Ha kept fixed throughout the t...

The magnetizations 〈M⊥〉 of strips of BiSCCO tapes are seen to evolve towards a common diamagnetic 〈M⊥〉 versus H⊥ curve, hence display quasi-reversibility, from the application of a few cycles of a magnetic field H∥ directed along their length, when previously magnetized, (i) to critical paramagnetic or diamagnetic states along the major hysteresis...

The model proposed by Tent et al. [Phys. Rev. B 58, 11 761 (1998)] to account for the angle dependence they observed in the magnetization 〈M〉 of a single-domain sphere in a series of zero-field-cooled hysteresis loop measurements with warmups above Tc between each measurement at a specific angle, is presented in a different perspective. Calculated...