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Search Publications by: Albert Davydov (Fed)

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Displaying 51 - 75 of 176

In situ transport measurements reveal source of mobility enhancement of MoS2 and MoTe2 during dielectric deposition

April 21, 2020
Author(s)
Ju Ying Shang, Michael J. Moody, Jiazhen Chen, Sergiy Krylyuk, Albert Davydov, Tobin J. Marks, Lincoln J. Lauhon
Layered transition metal dichalcogenides (TMDs) and two-dimensional (2D) materials are widely studied as complements to Si complementary metal-oxide-semiconductor technology. Field-effect transistors (FETs) made with 2D materials often exhibit mobilities

Comparable Enhancement of TERS signals from WeSe2 on Chromium and Gold.

April 6, 2020
Author(s)
Albert Davydov, Sergiy Krylyuk, Angela R. Hight Walker, Bojan R. Ilic, Andrey Krayev, Ashish Bhattarai, Alan G. Joly, Matej Velicky, Patrick Z. El-Khoury
Plasmonic tip-sample junctions, at which the incident and scattered optical fields are localized and optimally enhanced, are often exploited to achieve ultrasensitive and highly spatially localized tip-enhanced Raman scattering (TERS). Recent work has

Doping of MoTe2 via surface charge-transfer in ambient air

March 19, 2020
Author(s)
Gheorghe Stan, Cristian Ciobanu, Sri Ranga Jai Likith, Asha Rani, Sergiy Krylyuk, Albert Davydov
Doping is a key process that facilitates the use of semiconductors for electronic and optoelectronic devices, by which the concentration and type of majority carriers (electrons or holes) can be modified controllably to achieve desired conduction

Valley Phenomena in the Candidate Phase Change Material WSe2(1-x)Te2x

January 15, 2020
Author(s)
Sean M. Oliver, Joshua Young, Sergiy Krylyuk, Thomas L. Reinecke, Albert Davydov, Patrick M. Vora
Alloyed transition metals dichalcogenides (TMDs) provide the unique opportunity for coupling band engineering and valleytronic phenomena in an atomically-thin platform. However, valley properties remain largely unexplored in TMD alloys. Here, we

Dielectric properties of Nb_x}W_1-x}Se_2} alloys

December 16, 2019
Author(s)
Albert Rigosi, Heather M. Hill, Sergiy Krylyuk, Nhan V. Nguyen, Angela Hight Walker, Albert Davydov, David Newell
The growth of transition metal dichalcogenide (TMDC) alloys provides an opportunity to experimentally access information elucidating how optical properties change with gradual substitutions in the lattice compared with their pure compositions. In this work

Near-infrared photonic phase-change properties of transition metal ditellurides.

September 23, 2019
Author(s)
Albert Davydov, Sergiy Krylyuk, Yifei Li, Akshay Singh, Rafael Jaramillo
We use the (Mo,W)Te2 system to explore the potential of transition metal dichalcogenides (TMDs) as phasechange materials for integrated photonics. We measure the complex optical constant of MoTe2 in both the 2H and 1T’ phases by spectroscopic ellipsometry

Automated Mechanical Exfoliation of MoS2 and MoTe2 Layers for 2D Materials Applications

September 13, 2019
Author(s)
Albert Davydov, Sergiy Krylyuk, Kyle J. DiCamillo, Makarand Paranjape, Wendy Shi
An automated technique is presented for mechanically exfoliating single-layer and few-layer transition metal dichalcogenides using controlled shear and normal forces imposed by a parallel plate rheometer. A thin sample that is removed from bulk MoS2 or

Thermal Stability of Titanium Contacts to MoS2

August 30, 2019
Author(s)
Huairuo Zhang, Albert Davydov, Leonid A. Bendersky, Keren M. Freedy, Stephen J. McDonnell
Thermal annealing of Ti contacts is commonly implemented in the fabrication of MoS2 devices however its effects on interface chemistry have not been previously reported in the literature. In this work, the thermal stability of titanium contacts deposited

MoS2 cleaning by acetone and UV-Ozone: Geological vs. synthetic material (Letter)

January 25, 2019
Author(s)
Keren M. Freedy, Sales G. Maria, Sergiy Krylyuk, Albert Davydov, Stephen J. McDonnell
The effects of poly(methyl methacrylate) PMMA removal procedures on the surface chemistry of both geological and chemical vapor deposited (CVD) MoS2 are investigated. X-ray photoelectron spectroscopy is employed following acetone dissolution, thermal

An Ultra-fast Multi-level MoTe2-based RRAM

January 17, 2019
Author(s)
Albert Davydov, Leonid A. Bendersky, Sergiy Krylyuk, Huairuo Zhang, Feng Zhang, Joerg Appenzeller, Pragya R. Shrestha, Kin P. Cheung, Jason P. Campbell
We report multi-level MoTe2-based resistive random-access memory (RRAM) devices with switching speeds of less than 5 ns due to an electric-field induced 2H to 2Hd phase transition. Different from conventional RRAM devices based on ionic migration, the

Black phosphorus tunneling field-effect transistors

December 21, 2018
Author(s)
Albert Davydov, Huairuo Zhang, Leonid A. Bendersky
Band-to-band tunneling field-effect transistors (TFETs)1-7 have emerged as promising candidates to replace conventional metal-oxide-semiconductor field-effect transistors (MOSFETs) for low-power integration circuits and have been demonstrated to overcome

Electric field induced phase transition in vertical MoTe2 and Mo1-xWxTe2 based RRAM devices

December 10, 2018
Author(s)
Feng Zhang, Sergiy Krylyuk, Huairuo Zhang, Cory A. Milligan, Dmitry Y. Zemlyanov, Leonid A. Bendersky, Albert Davydov, Joerg Appenzeller, Benjamin P. Burton, Yugi Zhu
Transition metal dichalcogenides have attracted attention as potential building blocks for various electronic applications due to their atomically thin nature and polymorphism. Here, we report an electric-field-induced structural transition from a 2H

Control of polarity in multilayer MoTe2 field-effect transistors by channel thickness

November 9, 2018
Author(s)
Albert Davydov, Mona Zaghloul, Sergiy Krylyuk, Ratan K. Debnath, Asha Rani, Kyle J. DiCamillo, Payam Taheri
In this study, electronic properties of field-effect transistors (FETs) fabricated from exfoliated MoTe2 single crystals are investigated as a function of channel thickness. The conductivity type in FETs gradually changes from n-type for thick MoTe2 layers

Predicting synthesizability

October 24, 2018
Author(s)
Albert Davydov, Ursula R. Kattner
Advancements in multiscale multi-physics computational materials design have led to accelerated discovery of advanced materials for energy, electronics and engineering applications. For most bulk materials synthesizing and processing procedures are

Electronic Characteristics of MoSe2 and MoTe2 for Nanoelectronic Applications

October 15, 2018
Author(s)
Asha Rani, Shiqi Guo, Sergiy Krylyuk, Albert Davydov
Single-crystalline MoSe2 and MoTe2 platelets were grown by Chemical Vapor Transport (CVT), followed by exfoliation, device fabrication, optical and electrical characterization. We observed that for the field-effect-transistor (FET) channel thickness in

Towards superconductivity in p-type delta-doped Si/Al/Si heterostructures

July 30, 2018
Author(s)
Aruna N. Ramanayaka, Hyun Soo Kim, Joseph A. Hagmann, Roy E. Murray, Ke Tang, Neil M. Zimmerman, Curt A. Richter, Joshua M. Pomeroy, Frederick Meisenkothen, Huairuo Zhang, Albert Davydov, Leonid A. Bendersky
In pursuit of superconductivity in p-type silicon (Si), we are using a single atomic layer of aluminum (Al) sandwiched between a Si substrate and a thin Si epi-layer. The delta layer was fabricated starting from an ultra high vacuum (UHV) flash anneal of

Probing the Optical Properties and Strain-Tuning of Ultrathin Mo1-xWxTe2

March 21, 2018
Author(s)
Ozgur B. Aslan, Isha M. Datye, Michal J. Mleczko, Karen Lau, Sergiy Krylyuk, Alina Bruma, Irina Kalish, Albert Davydov, Eric Pop, Tony F. Heinz
Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin Mo0.91W0.09Te2, a semiconducting alloy of MoTe2, using Raman, photoluminescence

Electrochemical Detection of Acetaminophen with Silicon Nanowires

February 8, 2018
Author(s)
Raja Ram Pandey, Hussain S. Alshahrani, Sergiy Krylyuk, Elissa Williams, Albert Davydov, Charles C. Chusuei
Acetaminophen (APAP) is an antipyretic, analgesic agent. Overdose during medical treatment poses a risk for liver failure. Hence, it is important to develop methods to monitor APAP in the body to avoid APAP toxicity. Here, we report an efficient and

Nanoscale Heterogeneities in Monolayer MoSe2 Revealed by Correlated Scanning Probe Microscopy and Tip-Enhanced Raman Spectroscopy

December 26, 2017
Author(s)
Albert Davydov, Sergiy Krylyuk, Payam Taheri, Kirby K. Smithe, Andrey V. Krayev, Connor S. Bailey, Hye R. Lee, Eilam Yalon, Ozgur B. Aslan, Miguel M. Rojo, Tony F. Heinz, Eric Pop
Understanding growth, grain boundaries (GBs), and defects of emerging two-dimensional (2D) materials is key to enabling their future applications. For quick, non-destructive metrology, many studies rely on confocal Raman spectroscopy, whose spatial

Nanowire Aptasensors for Electrochemical Detection of Cell-Secreted Cytokines

October 9, 2017
Author(s)
Ying Liu, Ali Rahimian, Sergiy Krylyuk, Tam Vu, Bruno Crulhas, Gulnaz Stybayeva, Dong-Sik Shin, Albert Davydov, Alexander Revzin, Meruyert Imanbekova
Cytokines are small proteins secreted by immune cells in response to pathogens/infections; therefore these proteins can be used in diagnosing infectious diseases. For example, release of a cytokine interferon (IFN)-γ from T-cells is used for blood-based

The structural phases and vibrational properties of Mo1-xWxTe2 alloys

September 1, 2017
Author(s)
Sean M. Oliver, Ryan Beams, Sergiy Krylyuk, Arunima Singh, Irina Kalish, Alina Bruma, Francesca Tavazza, Iris Stone, Stephan J. Stranick, Albert Davydov, Patrick M. Vora
The structural polymorphism in transition metal dichalcogenides (TMDs) provides exciting opportunities for developing advanced electronics. For example, MoTe2 crystallizes in the 2H semiconducting phase at ambient temperature and pressure, but transitions