Publications (135)
Transition Metal Dichalcogenide Solar Cells for Indoor Energy Harvesting
Frederick U. Nitta, Koosha Nassiri Nazif, Eric Pop
With the rapid expansion of the Internet of Things (IoT), efficient and durable energy harvesters for powering IoT devices operating indoors and outdoors are imperative. Promising…
Annealing Free, Clean Graphene Transfer using Alternative Polymer Scaffolds
Joshua D. Wood, Gregory P. Doidge, Enrique A. Carrion +11
We examine the transfer of graphene grown by chemical vapor deposition (CVD) with polymer scaffolds of poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly(phthalaldehyd…
Reduction of Hysteresis for Carbon Nanotube Mobility Measurements Using Pulsed Characterization
David Estrada, Sumit Dutta, Albert Liao +1
We describe a pulsed measurement technique to suppress hysteresis for carbon nanotube (CNT) device measurements in air, vacuum, and over a wide temperature range (80-453 K). Varyin…
Localized Triggering of the Insulator-Metal Transition in VO2 using a Single Carbon Nanotube
Stephanie M. Bohaichuk, Miguel Muñoz Rojo, Gregory Pitner +8
Vanadium dioxide (VO2) has been widely studied for its rich physics and potential applications, undergoing a prominent insulator-metal transition (IMT) near room temperature. The t…
Direct observation of nanometer-scale Joule and Peltier effects in phase change memory devices
Kyle L. Grosse, Feng Xiong, Sungduk Hong +2
We measure power dissipation in phase change memory (PCM) devices by scanning Joule ex-pansion microscopy (SJEM) with ~50 nm spatial and 0.2 K temperature resolution. The temperatu…
The Role of Electrical and Thermal Contact Resistance for Joule Breakdown of Single-Wall Carbon Nanotubes
Eric Pop
Several data sets of electrical breakdown in air of single-wall carbon nanotubes (SWNTs) on insulating substrates are collected and analyzed. A universal scaling of the Joule break…
Biaxial Tensile Strain Enhances Electron Mobility of Monolayer Transition Metal Dichalcogenides
Jerry A. Yang, Robert K. A. Bennett, Lauren Hoang +7
Strain engineering can modulate the material properties of two-dimensional (2D) semiconductors for electronic and optoelectronic applications. Recent theory and experiments have fo…
High-Performance Flexible Nanoscale Field-Effect Transistors Based on Transition Metal Dichalcogenides
Alwin Daus, Sam Vaziri, Victoria Chen +7
Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) are good candidates for high-performance flexible electronics. However, most demonstrations of such flex…
Lateral Transport and Field-Effect Characteristics of Sputtered P-Type Chalcogenide Thin Films
Sumaiya Wahid, Alwin Daus, Asir Intisar Khan +4
Investigating lateral electrical transport in p-type thin film chalcogenides is important to evaluate their potential for field-effect transistors (FETs) and phase-change memory ap…
Engineering Thermal and Electrical Interface Properties of Phase Change Memory with Monolayer MoS2
Christopher M. Neumann, Kye L. Okabe, Eilam Yalon +3
Phase change memory (PCM) is an emerging data storage technology, however its programming is thermal in nature and typically not energy-efficient. Here we reduce the switching powe…
Improved Contacts to MoS2 Transistors by Ultra-High Vacuum Metal Deposition
Chris D. English, Gautam Shine, Vincent E. Dorgan +2
The scaling of transistors to sub-10 nm dimensions is strongly limited by their contact resistance (Rc). Here we present a systematic study of scaling MoS2 devices and contacts wit…
Electrically driven thermal light emission from individual single-walled carbon nanotubes
David Mann, Y. K. Kato, Anika Kinkhabwala +7
Light emission from nanostructures exhibits rich quantum effects and has broad applications. Single-walled carbon nanotubes (SWNTs) are one-dimensional (1D) metals or semiconductor…
How to Report and Benchmark Emerging Field-Effect Transistors
Zhihui Cheng, Chin-Sheng Pang, Peiqi Wang +13
Emerging low-dimensional nanomaterials have been studied for decades in device applications as field-effect transistors (FETs). However, properly reporting and comparing device per…
Avalanche-Induced Current Enhancement in Semiconducting Carbon Nanotubes
Albert Liao, Yang Zhao, Eric Pop
Semiconducting carbon nanotubes under high electric field stress (~10 V/um) display a striking, exponential current increase due to avalanche generation of free electrons and holes…
Surface conduction and reduced electrical resistivity in ultrathin noncrystalline NbP semimetal
Asir Intisar Khan, Akash Ramdas, Emily Lindgren +9
The electrical resistivity of conventional metals, such as copper, is known to increase in thin films due to electron-surface scattering, limiting the performance of metals in nano…
Energy Dissipation and Transport in Nanoscale Devices
Eric Pop
Understanding energy dissipation and transport in nanoscale structures is of great importance for the design of energy-efficient circuits and energy-conversion systems. This is als…
Layer Dependent Interfacial Transport and Optoelectrical Properties of MoS2 on Ultra-flat Metals
Hao Lee, S. Deshmukh, Jing Wen +7
Transition metal dichalcogenides (TMDs) are layered semiconducting van der Waal crystals and promising materials for a wide range of electronic and optoelectronic devices. Realizin…
An electrochemical thermal transistor
Aditya Sood, Feng Xiong, Shunda Chen +9
The ability to actively regulate heat flow at the nanoscale could be a game changer for applications in thermal management and energy harvesting. Such a breakthrough could also ena…
Effect of Grain Boundaries on Thermal Transport in Graphene
Andrey Y. Serov, Zhun-Yong Ong, Eric Pop
We investigate the influence of grain boundaries (GBs), line defects (LDs), and chirality on thermal transport in graphene using non-equilibrium Green's functions. At room temperat…
Reduced Thermal Conductivity of Supported and Encased Monolayer and Bilayer MoS
Alexander J. Gabourie, Saurabh V. Suryavanshi, Amir Barati Farimani +1
Electrical and thermal properties of atomically thin two-dimensional (2D) materials are affected by their environment, e.g. through remote phonon scattering or dielectric screening…
High Current Density in Monolayer MoS Doped by AlO
Connor J. McClellan, Eilam Yalon, Kirby K. H. Smithe +2
Semiconductors require stable doping for applications in transistors, optoelectronics, and thermoelectrics. However, this has been challenging for two-dimensional (2D) materials, w…
Role of Pressure in the Growth of Hexagonal Boron Nitride Thin Films from Ammonia-Borane
Justin C. Koepke, Joshua D. Wood, Enrique A. Carrion +14
We analyze the optical, chemical, and electrical properties of chemical vapor deposition (CVD) grown hexagonal boron nitride (h-BN) using the precursor ammonia-borane ()…
How to Identify Suitable Gate Dielectrics for Transistors based on Two-Dimensional Semiconductors
Theresia Knobloch, Quentin Smets, Anton E. O. Persson +23
The recent progress in nanosheet transistors has established two-dimensional (2D) semiconductors as viable candidates for future ultra-scaled electronic devices. Next to reducing c…
Scaling Theory of Two-Dimensional Field Effect Transistors
Saurabh V. Suryavanshi, Chris D. English, H. -S. P. Wong +1
We present a scaling theory of two-dimensional (2D) field effect transistors (FETs). For devices with channel thickness less than 4 nm, the device electrostatics is dominated by th…
Electrically driven programmable phase-change meta-switch reaching 80% efficiency
Sajjad Abdollahramezani, Omid Hemmatyar, Mohammad Taghinejad +11
Despite recent advances in active metaoptics, wide dynamic range combined with high-speed reconfigurable solutions is still elusive. Phase-change materials (PCMs) offer a compellin…
Thermally-Limited Current Carrying Ability of Graphene Nanoribbons
Albert D. Liao, Justin Z. Wu, Xinran Wang +4
We investigate high-field transport in graphene nanoribbons (GNRs) on SiO2, up to breakdown. The maximum current density is limited by self-heating, but can reach >3 mA/um for GNRs…
Effects of Tip-Nanotube Interactions on Atomic Force Microscopy Imaging of Carbon Nanotubes
Rouholla Alizadegan, Albert D. Liao, Feng Xiong +2
We examine the effect of van der Waals (vdW) interactions between atomic force microscope (AFM) tips and individual carbon nanotubes (CNTs) supported on SiO2. Molecular dynamics (M…
Direct Exfoliation of Nanoribbons from Bulk van der Waals Crystals
Ashley P. Saunders, Victoria Chen, Jierong Wang +8
Confinement of monolayers into quasi-one-dimensional atomically-thin nanoribbons could lead to novel quantum phenomena beyond those achieved in their bulk and monolayer counterpart…
Scanning Tunneling Microscopy Study and Nanomanipulation of Graphene-Coated Water on Mica
Kevin T. He, Joshua D. Wood, Gregory P. Doidge +2
We study interfacial water trapped between a sheet of graphene and a muscovite (mica) surface using Raman spectroscopy and ultra-high vacuum scanning tunneling microscopy (UHV-STM)…
Role of remote interfacial phonon (RIP) scattering in heat transport across graphene/SiO2 interfaces
Yee Kan Koh, Austin S. Lyons, Myung-Ho Bae +4
Heat transfer across interfaces of graphene and polar dielectrics (e.g. SiO2) could be mediated by direct phonon coupling, as well as electronic coupling with remote interfacial ph…
Engineering thermal transport across layered graphene-MoS2 superlattices
Aditya Sood, Charles Sievers, Yong Cheol Shin +7
Layering two-dimensional van der Waals materials provides unprecedented control over atomic placement, which could enable tailoring of vibrational spectra and heat flow at the sub-…
Thermal Conductivity of Chirality-Sorted Carbon Nanotube Networks
Feifei Lian, Juan P. Llinas, Zuanyi Li +2
The thermal properties of single-walled carbon nanotubes (SWNTs) are of significant interest, yet their dependence on SWNT chirality has been, until now, not explored experimentall…
Photoresponse of Natural van der Waals Heterostructures
Kyle Ray, Alexander E. Yore, Tong Mou +5
Van der Waals (vdW) heterostructures consisting of two dimensional materials offer a platform to obtain material by design and are very attractive owing to novel electronic states.…
Substrate-supported thermometry platform for nanomaterials like graphene, nanotubes, and nanowires
Zuanyi Li, Myung-Ho Bae, Eric Pop
We demonstrate a substrate-supported thermometry platform to measure thermal conduction in nanomaterials like graphene, with no need to suspend them. We use three-dimensional simul…
Graphene-Based Electromechanical Thermal Switches
Michelle E. Chen, Miguel Muñoz Rojo, Feifei Lian +8
Thermal management is an important challenge in modern electronics, avionics, automotive, and energy storage systems. While passive thermal solutions (like heat sinks or heat sprea…
Semimetal-Monolayer Transition Metal Dichalcogenides Photodetectors for Wafer-Scale Ultraviolet Photonics
Hon-Loen Sinn, Aravindh Kumar, Eric Pop +1
Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs), such as MoS, are promising candidates for nanoscale photonics because of strong-light matter inter…
A Compact Virtual-Source Model for Carbon Nanotube Field-Effect Transistors in the Sub-10-nm Regime-Part I Intrinsic Elements
Chi-Shuen Lee, Eric Pop, Aaron D. Franklin +2
We presents a data-calibrated compact model of carbon nanotube (CNT) field-effect transistors (CNFETs) based on the virtual-source (VS) approach, describing the intrinsic current-v…
Strongly Tunable Anisotropic Thermal Transport in MoS2 by Strain and Lithium Intercalation: First--Principles Calculations
Shunda Chen, Aditya Sood, Eric Pop +2
The possibility of tuning the vibrational properties and the thermal conductivity of layered van der Waals materials either chemically or mechanically paves the way to significant…
Low Resistance P-type Contacts to Monolayer WSe through Chlorinated Solvent Doping
Lauren Hoang, Robert K. A. Bennett, Anh Tuan Hoang +7
Tungsten diselenide (WSe) is a promising p-type semiconductor limited by high contact resistance () and the lack of a reliable doping strategy. Here, we demonstra…
Nonvolatile electrically reconfigurable integrated photonic switch
Jiajiu Zheng, Zhuoran Fang, Changming Wu +8
Reconfigurability of photonic integrated circuits (PICs) has become increasingly important due to the growing demands for electronic-photonic systems on a chip driven by emerging a…
Frequency and Polarization Dependence of Thermal Coupling between Carbon Nanotubes and SiO2
Zhun-Yong Ong, Eric Pop
We study heat dissipation from a (10,10) CNT to a SiO2 substrate using equilibrium and non-equilibrium classical molecular dynamics. The CNT-substrate thermal boundary conductance…
Cross-Domain Acceleration of Open Modification Search: From Commodity Platforms to Emerging Memory and Storage Devices
Sumukh Pinge, Chang Eun Song, Po-Kai Hsu +10
Open modification search (OMS) in mass spectrometry (MS) is a data-intensive workload whose performance is dominantly limited by reference data movement rather than computation. Pr…
How do Quantum Effects Influence the Capacitance and Carrier Density of Monolayer MoS Transistors?
Robert K. A. Bennett, Eric Pop
When transistor gate insulators have nanometer-scale equivalent oxide thickness (EOT), the gate capacitance () becomes smaller than the oxide capacitance ($C_\textrm{…
Inducing Chalcogenide Phase Change with Ultra-Narrow Carbon Nanotube Heaters
Feng Xiong, Albert Liao, Eric Pop
Carbon nanotube (CNT) heaters with sub-5 nm diameter induce highly localized phase change in Ge2Sb2Te5 (GST) chalcogenide. A significant reduction in resistance of test structures…
Dynamic hybrid metasurfaces
Sajjad Abdollahramezani, Omid Hemmatyar, Mohammad Taghinejad +10
Efficient hybrid plasmonic-photonic metasurfaces that simultaneously take advantage of the potential of both pure metallic and all-dielectric nanoantennas are identified as an emer…
Temperature Dependent Thermal Boundary Conductance of Monolayer MoS by Raman Thermometry
Eilam Yalon, Ãzgür Burak Aslan, Kirby K. H. Smithe +9
The electrical and thermal behavior of nanoscale devices based on two-dimensional (2D) materials is often limited by their contacts and interfaces. Here we report the temperature-d…
Wide-field Hyperspectral Optical Microscopy for Rapid Characterization of Two-Dimensional Semiconductors and Heterostructures
Zhenghan Peng, Adeyemi Uthman, Zhepeng Zhang +4
Electronic and optoelectronic applications of two-dimensional (2D) semiconductors demand precise control over material quality, including thickness, composition, doping, and defect…
High-field Breakdown and Thermal Characterization of Indium Tin Oxide Transistors
Haotian Su, Yuan-Mau Lee, Tara Peña +9
Amorphous oxide semiconductors are gaining interest for logic and memory transistors compatible with low-temperature fabrication. However, their low thermal conductivity and hetero…
Hysteresis-Free Nanosecond Pulsed Electrical Characterization of Top-Gated Graphene Transistors
Enrique A. Carrion, Andrey Y. Serov, Sharnali Islam +6
We measure top-gated graphene field effect transistors (GFETs) with nanosecond-range pulsed gate and drain voltages. Due to high-k dielectric or graphene imperfections, the drain c…
Negative Differential Conductance and Hot Phonons in Suspended Nanotube Molecular Wires
Eric Pop, David Mann, Jien Cao +3
Freely suspended metallic single-wall carbon nanotubes (SWNTs) exhibit reduced current carrying ability compared to those lying on substrates, and striking negative differential co…
High-current p-type transistors from precursor-engineered synthetic monolayer WSe
Anh Tuan Hoang, Kathryn Neilson, Kaikui Xu +11
Monolayer tungsten diselenide (WSe) is a leading candidate for nanoscale complementary logic. However, high defect densities introduced during thin-film growth and device fabri…
Direct X-Ray Measurements of Strain in Monolayer MoS from Capping Layers and Geometrical Features
Kathryn Neilson, Marc Jaikissoon, Dante Zakhidov +4
Strain induced through fabrication, both by patterning and capping, can be used to change the properties of two-dimensional (2D) materials or other thin films. Here, we explore how…
Uncovering the Effects of Metal Contacts on Monolayer MoS2
Kirstin Schauble, Dante Zakhidov, Eilam Yalon +11
Metal contacts are a key limiter to the electronic performance of two-dimensional (2D) semiconductor devices. Here we present a comprehensive study of contact interfaces between se…
Enhanced Meta-Displays Using Advanced Phase-Change Materials
Omid Hemmatyar, Sajjad Abdollahramezani, Ioannis Zeimpekis +12
Structural colors generated due to light scattering from static all-dielectric metasurfaces have successfully enabled high-resolution, high-saturation, and wide-gamut color printin…
Flexible radiofrequency carbon nanotube transistors operating at frequencies above 100 GHz
Fan Xia, Tian Xia, Haotian Su +12
The development of the sixth generation of wireless communications technology (6G) requires terminals that can operate at frequencies above 100 GHz. For human-centric applications,…
Toward Low-Temperature Solid-Source Synthesis of Monolayer MoS2
Alvin Tang, Aravindh Kumar, Marc Jaikissoon +3
Two-dimensional (2D) semiconductors have been proposed for heterogeneous integration with existing silicon technology; however, their chemical vapor deposition (CVD) growth tempera…
Size scaling, dynamics, and electro-thermal bifurcation of VO2 Mott oscillators
Stephanie M. Bohaichuk, Suhas Kumar, Miguel Muñoz Rojo +7
Traditional electronic devices are well-known to improve in speed and energy-efficiency as their dimensions are reduced to the nanoscale. However, this scaling behavior remains unc…
Temperature and Gas-Environment Dependent Electron and Phonon Transport in Suspended Carbon Nanotubes Up to Electrical Breakdown
David Mann, Eric Pop, Jien Cao +3
High bias electrical transport characteristics of freely suspended metallic single-walled carbon nanotubes (SWNTs) are investigated at 250-400K in vacuum and various gases. Self-he…
Stateful Logic using Phase Change Memory
Barak Hoffer, Nicolás Wainstein, Christopher M. Neumann +3
Stateful logic is a digital processing-in-memory technique that could address von Neumann memory bottleneck challenges while maintaining backward compatibility with standard von Ne…
Nanoscale Phase Change Memory with Graphene Ribbon Electrodes
Ashkan Behnam, Feng Xiong, Andrea Cappelli +9
Phase change memory (PCM) devices are known to reduce in power consumption as the bit volume and contact area of their electrodes are scaled down. Here, we demonstrate two types of…
Channel-last gate-all-around nanosheet oxide semiconductor transistors
Fabia F. Athena, Xiangjin Wu, Nathaniel S. Safron +18
As we move beyond the era of transistor miniaturization, back-end-of-line-compatible transistors that can be stacked monolithically in the third dimension promise improved performa…
Thermal Dissipation and Variability in Electrical Breakdown of Carbon Nanotube Devices
Albert Liao, Rouholla Alizadegan, Zhun-Yong Ong +3
We study high-field electrical breakdown and heat dissipation from carbon nanotube (CNT) devices on SiO2 substrates. The thermal "footprint" of a CNT caused by van der Waals intera…
Imaging the electron charge density in monolayer MoS2 at the à ngstrom scale
Joel Martis, Sandhya Susarla, Archith Rayabharam +15
Four-dimensional scanning transmission electron microscopy (4D-STEM) has recently gained widespread attention for its ability to image atomic electric fields with sub-Ã ngstrom spa…
S2DS: Physics-Based Compact Model for Circuit Simulation of Two-Dimensional Semiconductor Devices Including Non-Idealities
Saurabh V. Suryavanshi, Eric Pop
We present a physics-based compact model for two-dimensional (2D) field-effect transistors (FETs) based on monolayer semiconductors such as MoS2. A semi-classical transport approac…
Impact of Phonon Surface Roughness Scattering on Thermal Conductivity of Thin Si Nanowires
Pierre Martin, Zlatan Aksamija, Eric Pop +1
We present a novel approach for computing the surface roughness-limited thermal conductivity of silicon nanowires with diameter D < 100 nm. A frequency-dependent phonon scattering…
SpecPCM: A Low-power PCM-based In-Memory Computing Accelerator for Full-stack Mass Spectrometry Analysis
Keming Fan, Ashkan Moradifirouzabadi, Xiangjin Wu +6
Mass spectrometry (MS) is essential for proteomics and metabolomics but faces impending challenges in efficiently processing the vast volumes of data. This paper introduces SpecPCM…
Uncovering Phase Change Memory Energy Limits by Sub-Nanosecond Probing of Power Dissipation Dynamics
Keren Stern, Nicolás Wainstein, Yair Keller +4
Phase change memory (PCM) is one of the leading candidates for neuromorphic hardware and has recently matured as a storage class memory. Yet, energy and power consumption remain ke…
Improved Gradual Resistive Switching Range and 1000x On/Off Ratio in HfOx RRAM Achieved with a Thermal Barrier
Raisul Islam, Shengjun Qin, Sanchit Deshmukh +7
Gradual switching between multiple resistance levels is desirable for analog in-memory computing using resistive random-access memory (RRAM). However, the filamentary switching of…
Thermal properties of graphene: Fundamentals and applications
Eric Pop, Vikas Varshney, Ajit K. Roy
Graphene is a two-dimensional (2D) material with over 100-fold anisotropy of heat flow between the in-plane and out-of-plane directions. High in-plane thermal conductivity is due t…
Thermal Boundary Conductance of Two-Dimensional Interfaces
Saurabh V. Suryavanshi, Alexander J. Gabourie, Amir Barati Farimani +1
Understanding the thermal properties of two-dimensional (2D) materials and devices is essential for thermal management of 2D applications. Here we perform molecular dynamics simula…
High-Specific-Power Flexible Transition Metal Dichalcogenide Solar Cells
Koosha Nassiri Nazif, Alwin Daus, Jiho Hong +13
Semiconducting transition metal dichalcogenides (TMDs) are promising for flexible high-specific-power photovoltaics due to their ultrahigh optical absorption coefficients, desirabl…
Intrinsic Electrical Transport and Performance Projections of Synthetic Monolayer MoS2 Devices
Kirby K. H. Smithe, Chris D. English, Saurabh V. Suryavanshi +1
We demonstrate monolayer MoS2 grown by chemical vapor deposition (CVD) with transport properties comparable to those of the best exfoliated devices over a wide range of carrier den…
Significant Phonon Drag Enables High Power Factor in the AlGaN/GaN Two-Dimensional Electron Gas
Ananth Saran Yalamarthy, Miguel Muñoz Rojo, Alexandra Bruefach +6
In typical thermoelectric energy harvesters and sensors, the Seebeck effect is caused by diffusion of electrons or holes in a temperature gradient. However, the Seebeck effect can…
SANTA: Self-Aligned Nanotrench Ablation via Joule Heating for Probing Sub-20 nm Devices
Feng Xiong, Sanchit Deshmukh, Sungduk Hong +4
Manipulating materials at the nanometer scale is challenging, particularly if alignment with nanoscale electrodes is desired. Here we describe a lithography-free, self-aligned nano…
CMOS-compatible Strain Engineering for High-Performance Monolayer Semiconductor Transistors
Marc Jaikissoon, ÃaÄıl KöroÄlu, Jerry A. Yang +3
Strain engineering has played a key role in modern silicon electronics, having been introduced as a mobility booster in the 1990s and commercialized in the early 2000s. Achieving s…
Mobility and Threshold Voltage Extraction in Transistors with Gate-Voltage-Dependent Contact Resistance
Robert K. A. Bennett, Lauren Hoang, Connor Cremers +2
The mobility of emerging (e.g., two-dimensional, oxide, organic) semiconductors is commonly estimated from transistor current-voltage measurements. However, such devices often expe…
Vibrational Properties of a Naturally Occurring Semiconducting van der Waals heterostructure
V. Z. Costa, Liangbo Liang, Sam Vaziri +3
We present vibrational properties of Franckeite, which is a naturally occurring van der Waals heterostructure consisting of two different semiconducting layers. Franckeite is a com…
Electrical power dissipation in carbon nanotubes on single crystal quartz and amorphous SiO2
Cheng-Lin Tsai, Albert Liao, Eric Pop +1
Heat dissipation in electrically biased semiconducting carbon nanotubes (CNTs) on single crystal quartz and amorphous SiO2 is examined with temperature profiles obtained by spatial…
Graphene-Based Platform for Infrared Near-Field Nanospectroscopy of Water and Biological Materials in an Aqueous Environment
Omar Khatib, Joshua D. Wood, Alexander S. McLeod +12
Scattering scanning near-field optical microscopy (s-SNOM) has emerged as a powerful nanoscale spectroscopic tool capable of characterizing individual biomacromolecules and molecul…
Scaling Nanoribbon Transistors with Monolayer Transition Metal Dichalcogenides
Tara Peña, Anton E. O. Persson, Andrey Krayev +13
Nanoscale transistors require aggressive reduction of all channel dimensions: length, width, and thickness. While monolayer two-dimensional semiconductors (2DS) offer ultimate thic…
Thermally and Molecularly Stimulated Relaxation of Hot Phonons in Suspended Carbon Nanotubes
David Mann, Eric Pop, Jien Cao +3
The high-bias electrical transport properties of suspended metallic single-walled carbon nanotubes (SWNTs) are investigated at various temperatures in vacuum, in various gases and…
Gate Dielectric Engineering with an Ultrathin Silicon-oxide Interfacial Dipole Layer for Low-Leakage Oxide-Semiconductor Memories
Fabia F. Athena, Jonathan Hartanto, Matthias Passlack +11
We demonstrate a gate dielectric engineering approach leveraging an ultrathin, atomic layer deposited (ALD) silicon oxide interfacial layer (SiL) between the amorphous oxide semico…
Imaging, simulation, and electrostatic control of power dissipation in graphene devices
Myung-Ho Bae, Zhun-Yong Ong, David Estrada +1
We directly image hot spot formation in functioning mono- and bilayer graphene field effect transistors (GFETs) using infrared thermal microscopy. Correlating with an electrical-th…
Electrical and Thermal Transport in Metallic Single-Wall Carbon Nanotubes on Insulating Substrates
Eric Pop, David Mann, Kenneth Goodson +1
We analyze transport in metallic single-wall carbon nanotubes (SWNTs) on insulating substrates over the bias range up to electrical breakdown in air. To account for Joule self-heat…
Non-volatile Phase-only Transmissive Spatial Light Modulators
Zhuoran Fang, Rui Chen, Johannes E. Fröch +14
Free-space modulation of light is crucial for many applications, from light detection and ranging to virtual or augmented reality. Traditional means of modulating free-space light…
Theoretical analysis of high-field transport in graphene on a substrate
Andrey Y. Serov, Zhun-Yong Ong, Massimo V. Fischetti +1
We investigate transport in graphene supported on various dielectrics (SiO2, BN, Al2O3, HfO2) through a hydrodynamic model which includes self-heating and thermal coupling to the s…
Thermal Transport Across Graphene Step Junctions
Miguel Munoz Rojo, Zuanyi Li, Charles Sievers +8
Step junctions are often present in layered materials, i.e. where single-layer regions meet multi-layer regions, yet their effect on thermal transport is not understood to date. He…
Excitation laser energy dependence of the gap-mode TERS spectra of WS and MoS on silver
Andrey Krayev, Eleonora Isotta, Lauren Hoang +8
We present a systematic study of the dependence of gap mode tip-enhanced Raman scattering (TERS) of mono- and bi-layer WS and MoS as a function of excitation laser energy.…
Chemically Tailored Growth of 2D Semiconductors via Hybrid Metal-Organic Chemical Vapor Deposition
Zhepeng Zhang, Lauren Hoang, Marisa Hocking +8
Two-dimensional (2D) semiconducting transition-metal dichalcogenides (TMDCs) are an exciting platform for new excitonic physics and next-generation electronics, creating a strong d…
Tuning Electrical and Thermal Transport in AlGaN/GaN Heterostructures via Buffer Layer Engineering
Ananth Saran Yalamarthy, Hongyun So, Miguel Muñoz Rojo +4
Over the last decade, progress in wide bandgap, III-V materials systems based on gallium nitride (GaN) has been a major driver in the realization of high power and high frequency e…
Bright visible light emission from graphene
Young Duck Kim, Hakseong Kim, Yujin Cho +18
Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible, and transparent optoelectronics. In particular, the strong light-matter inter…
Non-equilibrium Phonon Thermal Resistance at MoS2/Oxide and Graphene/Oxide Interfaces
Weidong Zheng, Connor J. McClellan, Eric Pop +1
Accurate measurements and physical understanding of thermal boundary resistance (R) of two-dimensional (2D) materials are imperative for effective thermal management of 2D electron…
Effect of substrate modes on thermal transport in supported graphene
Zhun-Yong Ong, Eric Pop
We examine thermal transport in graphene supported on SiO2 using molecular dynamics simulations. Coupling to the substrate reduces the thermal conductivity (TC) of supported graphe…
Two-Dimensional h-BN and MoS2 as Diffusion Barriers for Ultra-Scaled Copper Interconnects
Chun-Li Lo, Massimo Catalano, Kirby K. H. Smithe +5
Copper interconnects in modern integrated circuits require ultra-thin barriers to prevent intermixing of Cu with surrounding dielectric materials. Conventional barriers rely on met…
High Current Density and Low Thermal Conductivity of Atomically Thin Semimetallic WTe2
Michal J. Mleczko, Runjie, Xu +6
Two-dimensional (2D) semimetals beyond graphene have been relatively unexplored in the atomically-thin limit. Here we introduce a facile growth mechanism for semimetallic WTe2 crys…
Strain-Enhanced Mobility of Monolayer MoS2
Isha M. Datye, Alwin Daus, Ryan W. Grady +3
Strain engineering is an important method for tuning the properties of semiconductors and has been used to improve the mobility of silicon transistors for several decades. Recently…
Deep Learning to Automate Parameter Extraction and Model Fitting of Two-Dimensional Transistors
Robert K. A. Bennett, Jan-Lucas Uslu, Harmon F. Gault +8
We present a deep learning approach to extract physical parameters (e.g., mobility, Schottky contact barrier height, defect profiles) of two-dimensional (2D) transistors from elect…
The Heat Conduction Renaissance
Aditya Sood, Eric Pop, Mehdi Asheghi +1
Some of the most exciting recent advancements in heat conduction physics have been motivated, enabled, or achieved by the thermal management community that ITherm serves so effecti…
Contact Engineering High Performance n-Type MoTe2 Transistors
Michal J. Mleczko, Andrew C. Yu, Christopher M. Smyth +7
Semiconducting MoTe2 is one of the few two-dimensional (2D) materials with a moderate band gap, similar to silicon. However, this material remains under-explored for 2D electronics…
Role of Joule Heating on Current Saturation and Transient Behavior of Graphene Transistors
Sharnali Islam, Zuanyi Li, Vincent E. Dorgan +2
We use simulations to examine current saturation in sub-micron graphene transistors on SiO2/Si. We find self-heating is partly responsible for current saturation (lower output cond…