A5076978179- 2D Materials and Applications
- Advanced Memory and Neural Computing
- X-ray Diffraction in Crystallography
- Ferroelectric and Negative Capacitance Devices
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- MXene and MAX Phase Materials
- Nanowire Synthesis and Applications
- Machine Learning and ELM
- Perovskite Materials and Applications
- Graphene research and applications
- Gas Sensing Nanomaterials and Sensors
- Chalcogenide Semiconductor Thin Films
- ZnO doping and properties
- Advancements in Semiconductor Devices and Circuit Design
- Neural Networks and Reservoir Computing
- Digital Holography and Microscopy
- Neural Networks and Applications
- Neural dynamics and brain function
- Energy Harvesting in Wireless Networks
- Near-Field Optical Microscopy
- Quantum Dots Synthesis And Properties
- Advanced Thermodynamics and Statistical Mechanics
- Semiconductor materials and devices
- Machine Learning in Materials Science
Pennsylvania State University
2017-2022
Amrita Vishwa Vidyapeetham
2017
Abstract Here we benchmark device-to-device variation in field-effect transistors (FETs) based on monolayer MoS 2 and WS films grown using metal-organic chemical vapor deposition process. Our study involves 230 FETs 160 with channel lengths ranging from 5 μm down to 100 nm. We use statistical measures evaluate key FET performance indicators for benchmarking these two-dimensional (2D) transition metal dichalcogenide (TMD) monolayers against existing literature as well ultra-thin body Si FETs....
Realization of wafer-scale single-crystal films transition metal dichalcogenides (TMDs) such as WS2 requires epitaxial growth and coalescence oriented domains to form a continuous monolayer. The must be in the same crystallographic direction on substrate inhibit formation inversion domain boundaries (IDBs), which are common feature layered chalcogenides. Here we demonstrate fully coalesced unidirectional monolayers 2 in. diameter c-plane sapphire by metalorganic chemical vapor deposition...
Abstract Spiking neural networks (SNNs) promise to bridge the gap between artificial (ANNs) and biological (BNNs) by exploiting biologically plausible neurons that offer faster inference, lower energy expenditure, event-driven information processing capabilities. However, implementation of SNNs in future neuromorphic hardware requires encoders analogous sensory neurons, which convert external/internal stimulus into spike trains based on specific algorithm along with inherent stochasticity....
Dilute magnetic semiconductors (DMS), achieved through substitutional doping of spin-polarized transition metals into semiconducting systems, enable experimental modulation spin dynamics in ways that hold great promise for novel magneto-electric or magneto-optical devices, especially two-dimensional (2D) systems such as metal dichalcogenides accentuate interactions and activate valley degrees freedom. Practical applications 2D magnetism will likely require room-temperature operation, air...
Abstract In this article, we adopt a radical approach for next generation ultra-low-power sensor design by embracing the evolutionary success of animals with extraordinary sensory information processing capabilities that allow them to survive in extreme and resource constrained environments. Stochastic resonance (SR) is one those astounding phenomena, where noise, which considered detrimental electronic circuits communication systems, plays constructive role detection weak signals. Here,...
The recent decline in energy, size and complexity scaling of traditional von Neumann architecture has resurrected considerable interest brain-inspired computing. Artificial neural networks (ANNs) based on emerging devices, such as memristors, achieve brain-like computing but lack energy-efficiency. Furthermore, slow learning, incremental adaptation, false convergence are unresolved challenges for ANNs. In this article we, therefore, introduce Gaussian synapses heterostructures atomically...
The representation of external stimuli in the form action potentials or spikes constitutes basis energy efficient neural computation that emerging spiking networks (SNNs) aspire to imitate. With recent evidence suggesting information brain is more often represented by explicit firing times neurons rather than mean rates, it imperative develop novel hardware can accelerate sparse and spike-timing-based encoding. Here a medium-scale integrated circuit composed two cascaded three-stage...
Abstract Mobility is a critical parameter that routinely used for benchmarking the performance of field‐effect transistors (FETs) based on novel nanomaterials. In fact, mobility values are often to champion nanomaterials since high‐performance devices necessitate high values. The current belief contacts can only limit FET and hence extracted an underestimation true channel mobility. However, here, such misconception challenged through rigorous experimental effort, backed by numerical...
Abstract Artificial neural networks have demonstrated superiority over traditional computing architectures in tasks such as pattern classification and learning. However, they do not measure uncertainty predictions, hence can make wrong predictions with high confidence, which be detrimental for many mission-critical applications. In contrast, Bayesian (BNNs) naturally include their model, the weights are represented by probability distributions (e.g. Gaussian distribution). Here we introduce...
Two-dimensional (2D) layered materials demonstrate their exquisite properties such as high temperature superconductivity, superlubricity, charge density wave, piezotronics, flextronics, straintronics, spintronics, valleytronics, and optoelectronics, mostly, at the monolayer limit. Following initial breakthroughs based on micromechanically exfoliated 2D monolayers, significant progress has been made in recent years toward bottom-up synthesis of large-area MoS2 WS2 using physical vapor...
In this paper, we report high-performance monolayer thin-film transistors (TFTs) based on a variety of two-dimensional layered semiconductors such as MoS2, WS2, and MoSe2 which were obtained from their corresponding bulk counterparts via an anomalous but high-yield low-cost electrochemical corrosion process, also referred to electro-ablation (EA), at room temperature. These TFTs demonstrated current ON–OFF ratios in excess 107 along with ON currents 120 μA/μm for 40 clearly outperform the...
Metaheuristic algorithms such as simulated annealing (SA) are often implemented for optimization in combinatorial problems, especially discreet problems. SA employs a stochastic search, where high-energy transitions ("hill-climbing") allowed with temperature-dependent probability to escape local optima. Ising spin glass systems have properties disorder and "frustration" provide problem high number of metastable states ground-state degeneracy. In this work, subthreshold Boltzmann transport is...
In this paper we provide insight into an anomalous corrosion process, referred to as electroablation (EA), which converts multilayer flakes of transition metal diselenides like MoSe2 their corresponding monolayers when micromechanically exfoliated on a conductive electrode and subsequently subjected high anodic potential inside conventional electrochemical cell. Photoluminescence intensity maps scanning transmission electron microscopy (STEM) images confirmed the single crystalline nature...
High throughput characterization and processing techniques are becoming increasingly necessary to navigate multivariable, data-driven design challenges for sensors electronic devices. For two-dimensional materials, device performance is highly dependent upon a vast array of material properties including the number layers, lattice strain, carrier concentration, defect density, grain structure. In this work, laser crystallization was used locally pattern transform hundreds regions amorphous...
Two-dimensional (2D) transition-metal dichalcogenides (TMDs) are a unique class of 2D materials possessing optoelectronic properties when exfoliated into mono- and few-layer sheets. Recently, electroablation (EA) has become interest as promising synthesis method for single-layer sheets TMDs. Here, we introduce spectroelectrochemical micro-extinction spectroscopy (SE-MExS) high-throughput technique to study electrochemical thinning TMDs it occurs. This approach enables the parallel use...
Digital holography has found applications in many walks of life, from medicine to metrology, due its ability measure complex fields. Here, we use the power digital quantitatively image two-dimensional Transition Metal Dichalcogenides (TMDs) such as MoS2 and WS2 placed on a SiO2/Si substrate determine their refractive indices or layer thicknesses. By considering different TMDs they are thinned down bulk monolayers by holographically capturing both amplitude phase reflected light, single...
Dilute magnetic semiconductors, achieved through substitutional doping of spin-polarized transition metals into semiconducting systems, enable experimental modulation spin dynamics in ways that hold great promise for novel magneto-electric or magneto-optical devices, especially two-dimensional systems such as metal dichalcogenides accentuate interactions and activate valley degrees freedom. Practical applications 2D magnetism will likely require room-temperature operation, air stability,...
Realization of wafer-scale single-crystal films transition metal dichalcogenides (TMDs) such as tungsten sulfide requires epitaxial growth and coalescence oriented domains to form a continuous monolayer. The must be in the same crystallographic direction on substrate avoid formation metallic inversion domain boundaries (IDBs) which are common feature layered chalcogenides. Here we demonstrate fully-coalesced single orientation monolayers 2-inch diameter c-plane sapphire by metalorganic...
Abstract Metaheuristic algorithms such as simulated annealing (SA) has been implemented for optimization in combinatorial problems, especially discreet problems. SA employs a stochastic search, where high-energy transitions (“hill-climbing”) are allowed with temperature-dependent probability to escape local optima. Ising spin glass systems have properties disorder and “frustration” provide problem high number of metastable states ground-state degeneracy. In this work, we exploit subthreshold...