Article
Nanoscience & Nanotechnology
Qi Zhang, Haoting Ying, Xin Li, Rong Xiang, Yongjia Zheng, Hemiao Wang, Jun Su, Minxuan Xu, Xin Zheng, Shigeo Maruyama, Xuefeng Zhang
Summary: This study reports the controlled doping of Sn heteroatoms into 2D MoS2 crystals through a single-step deposition method to improve the photo-detection ability, while preserving the host lattice. The substitutional doping process provides a potential platform to tune the properties of these 2D materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Yu-Jie Sun, Chang-Chun Ding, Wei Jin, Tong Liu, Jun-Shan Hu
Summary: In this study, a two-dimensional material called Haeckelite MoS2 was investigated as a catalyst for oxygen reduction reaction (ORR), and the ORR catalytic performance was further improved by doping transition metals.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Ling Jiang, Qian Zhou, Jing-Jing Li, Yu-Xin Xia, Huan-Xin Li, Yong-Jun Li
Summary: This article introduces a defect-predesigned strategy to produce MoS2 with single-atomic S vacancies by preparing Se-doped MoS2 and subsequent removing the Se. The results show that MoS2 with an optimal concentration of S vacancies exhibits outstanding HER performance.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Bidesh Mondal, Xiaolei Zhang, Sumit Kumar, Feng Long, Nirmal Kumar Katiyar, Mahesh Kumar, Saurav Goel, Krishanu Biswas
Summary: The demand for carbon-free energy sources has made the use of hydrogen (H2) gas increasingly important, but its explosive nature raises safety concerns. Researchers have developed a hydrogen gas detection sensor using high-entropy alloy nanoparticles, which shows high selectivity and sensitivity. By decorating the 2D MoS2 surface with these nanoparticles, the sensor can effectively adsorb and dissociate H2 gas, thereby improving its performance.
Article
Chemistry, Multidisciplinary
Junli Du, Qingliang Liao, Baishan Liu, Xiankun Zhang, Huihui Yu, Yang Ou, Jiankun Xiao, Zhuo Kang, Haonan Si, Zheng Zhang, Yue Zhang
Summary: A gate-controllable polarity-reversible photodiode based on ambipolar 2D semiconductors is proposed, which can manipulate the local carrier type and density profile to achieve polarity reversibility. The photodiode exhibits excellent rectifying behavior and photovoltaic performance, with reversible photovoltage polarity demonstrated under gate control.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Yae Zy Kang, Gwang Hwi An, Min-Gi Jeon, So Jeong Shin, Su Jin Kim, Min Choi, Jae Baek Lee, Tae Yeon Kim, Ikhwan Nur Rahman, Hyun Young Seo, Seyoung Oh, Byungjin Cho, Jihoon Choi, Hyun Seok Lee
Summary: This study demonstrates a significant increase in electrical mobility and reduced hysteresis in TMD-based FETs hybridized with metal halide perovskites. The injection of electrons from perovskites into TMDs induces heavy n-doping and repairs point defects, leading to improved performance.
Article
Chemistry, Multidisciplinary
Lifei Sun, Zhixing Lu, Rui Xu, Zhewei Li, Guanchen Xu, Fengen Chen, Zhihai Cheng, Liying Jiao
Summary: Two-dimensional transition metal dichalcogenides (TMDCs) have shown great potential in 2D nanoelectronic devices, but the stability of these devices has not been well explored. In this study, the degradation of MoS2 devices in ambient conditions was attributed to surface oxidation of the contact metals with low work function, leading to an increased contact barrier and hindered electron injection. By selectively doping the contacts with organolithium, the performance of aged devices was successfully recovered and the lifetime of MoS2 devices was prolonged. This work provides important insights into the stability of 2D TMDCs devices and offers a new approach for optimizing the performance of 2D MoS2 devices.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Nanoscience & Nanotechnology
Sangyeon Pak, Jiwon Son, Taehun Kim, Jungmoon Lim, John Hong, Younhee Lim, Chul-Joon Heo, Kyung-Bae Park, Yong Wang Jin, Kyung-Ho Park, Yuljae Cho, SeungNam Cha
Summary: A novel iodine gas doping method has been proposed to simultaneously modulate the electrical properties of both 2D MoS2 channel and 2D CuS electrode in a facile and cost-effective manner, allowing for the improvement of the control performance of electronic devices.
Article
Energy & Fuels
Derya Oncel Ozgur
Summary: This work presents a novel nickel@nitrogen-doped graphene@MoS2 (Ni@N-Gr/ MoS2) triad heterostructure for catalytic HER. The as-synthesized Ni@N-Gr/MoS2 assembly exhibits high intrinsic HER activity and stability, thanks to the incorporation of Ni@N-Gr in the basal plane of MoS2 and the improvement of conductivity by nitrogen-doped graphene.
Article
Materials Science, Multidisciplinary
Takahito Nishimura, Kento Nakaji, Jakapan Chantana, Abdurashid Mavlonov, Yu Kawano, Takayuki Negami, Takashi Minemoto
Summary: In this study, a p-type Nb-doped MoS2 film was developed under a H2S/Ar ambient and applied to chalcogenide thin-film solar cells. By adjusting the compositional ratio of Nb and Mo, the surface roughness and growth rate of the film were changed, as well as the conductivity type. Adding Nb atoms to the MoS2 film increased the carrier density and changed the conductivity type, resulting in improved performance of the chalcogenide solar cells.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Review
Chemistry, Physical
Saeed Sovizi, Robert Szoszkiewicz
Summary: This review presents the structural changes of MoS2 induced by various single atom dopants and their potential applications in energy storage, catalysis, sensing, etc. High resolution scanning transmission electron microscopy and scanning probe microscopy techniques have been used to study the dopant positions and sub-atomic structural changes in MoS2.
SURFACE SCIENCE REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Austin M. Evans, Kelsey A. Collins, Sangni Xun, Taylor G. Allen, Samik Jhulki, Ioannina Castano, Hannah L. Smith, Michael J. Strauss, Alexander K. Oanta, Lujia Liu, Lei Sun, Obadiah G. Reid, Gjergji Sini, Danilo Puggioni, James M. Rondinelli, Tijana Rajh, Nathan C. Gianneschi, Antoine Kahn, Danna E. Freedman, Hong Li, Stephen Barlow, Garry Rumbles, Jean-Luc Bredas, Seth R. Marder, William R. Dichtel
Summary: The bulk conductivity of 2D polymers (2DPs) can be enhanced by controlled n-doping. Optical and transient microwave spectroscopy measurements show that the n-doped 2DPs exhibit desired electronic properties. Density functional theory calculations reveal the main contribution to electronic conductivity in 2DPs. This study provides a new approach for synthesizing 2DPs with specific conductive properties.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Hanleem Lee, Sora Bak, Joosung Kim, Hyoyoung Lee
Summary: The study focuses on the effects of organic dopants reactivity on MoS2 and how it influences the electrical properties of MoS2. The band state of the dopants causes a proportional shift in the threshold voltages of the field-effect transistors, while on/off current ratio and mobility are strongly influenced by the defect density depending on the reactivity of the doping reaction. Through an in-depth study on the doping reaction, a solution-processed FET and a TFT with high mobility and a relatively high on/off ratio are successfully fabricated.
Article
Nanoscience & Nanotechnology
Jing Guo, Yu Liu, Ping-An Chen, Xincan Qiu, Huan Wei, Jiangnan Xia, Huajie Chen, Zebing Zeng, Lei Liao, Yuanyuan Hu
Summary: By forming van der Waals heterojunctions on 2D perovskite FETs and utilizing doping techniques to modify the electrical properties of organic semiconductor PDVT-10, the performance of the devices can be effectively tuned, with the added advantage of reversibility.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Li Gao, Xiankun Zhang, Huihui Yu, Mengyu Hong, Xiaofu Wei, Zhangyi Chen, Qinghua Zhang, Qingliang Liao, Zheng Zhang, Yue Zhang
Summary: Two-dimensional (2D) MoS2 is a promising channel material for next-generation integrated circuit (IC) transistors. However, the reliability of MoS2 is compromised by vacancy defects, particularly sulfur vacancies (V-S). Understanding the impact of these defects on transistor reliability has been challenging. In this study, we establish a simulated initiator to track the evolution of vacancy defects in MoS2 and their influence on transistor reliability.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Timothy D. Brown, Stephanie M. Bohaichuk, Mahnaz Islam, Suhas Kumar, Eric Pop, R. Stanley Williams
Summary: This study presents a model of VO2/SiN Mott threshold switches constructed using the principle of local activity. The model is refined to measurable material properties by considering a minimal set of quasistatic and dynamic electrical and thermal data. It accurately predicts electrical and thermal conductivities and capacitances, as well as locally active dynamics.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Asir Intisar Khan, Heshan Yu, Huairuo Zhang, John R. Goggin, Heungdong Kwon, Xiangjin Wu, Christopher Perez, Kathryn M. Neilson, Mehdi Asheghi, Kenneth E. Goodson, Patrick M. Vora, Albert Davydov, Ichiro Takeuchi, Eric Pop
Summary: Phase-change memory (PCM) is a promising candidate for data-intensive artificial intelligence applications, and achieving simultaneous attributes such as resistance changes and low resistance drift remains a challenge. In this study, nanoscale PCM devices based on a new phase-change nanocomposite material (Ge4Sb6Te7) demonstrated bi-directional gradual resistance changes with a large resistance window using low energy pulses. These devices showed multiple resistance levels with low resistance drift, high on/off ratio, and low variability, enabled by the unique properties of Ge4Sb6Te7. These findings advance the development of energy-efficient analog computing using PCM.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Cagil Koroglu, Eric Pop
Summary: As physical transistor scaling nears its limits and memory bandwidth becomes a bottleneck for many applications, three-dimensional (3D) integration offers a promising solution to continue Moore's law. Effective thermal management is essential to maximize the performance benefits of 3D integrated circuits (ICs), and using high thermal conductivity insulators like AlN and hBN can significantly reduce thermal resistance and overcome thermal challenges. In addition, highly anisotropic insulators such as hBN can be utilized as heat spreaders in memory-on-logic architectures to keep both memory and logic dies cool.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Yang Li, Wei Wang, Di Zhang, Maria Baskin, Aiping Chen, Shahar Kvatinsky, Eilam Yalon, Lior Kornblum
Summary: Resistive switching devices, utilizing a simple and scalable material system of conductive oxide interfaces, have been developed for memory and computation. These devices offer advantages in performance and energy efficiency, and the conductive oxide interface serves both as the bottom electrode and as a reservoir of defects for switching. This new device, based on scalable and CMOS-compatible fabrication processes, opens up new design possibilities.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Sumaiya Wahid, Alwin Daus, Jimin Kwon, Shengjun Qin, Jung-Soo Ko, H. -S. Philip Wong, Eric Pop
Summary: We report the performance and gate bias stress stability of ultrathin (similar to 4 nm) channel indium tin oxide (ITO) transistors using different precursors for atomic layer deposition (ALD) of the Al2O3 top-gate dielectric. Water-based ALD leads to devices remaining in the on-state, while ozone-based ALD devices have less negative V-T shift at short channel lengths and relatively more positive V-T at all channel lengths. We achieve maximum drive current and good gate bias stability with normalized VT shift, improving over previous reports of uncapped ITO transistors.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Emanuel Ber, Ryan W. Grady, Eric Pop, Eilam Yalon
Summary: This article explores the issue of contact resistance in atomically thin 2-D semiconductors, which hinders the integration of these materials into mainstream technology. The resistance is found to be influenced by the height and width of the Schottky barrier, as well as the number of transport modes for carrier injection. To reduce the contact resistance, a large number of transport modes can be achieved by increasing the number of channel carriers through heavy doping or gating.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Multidisciplinary
Victoria Chen, Hye Ryoung Lee, Cagil Koroglu, Connor J. McClellan, Alwin Daus, Eric Pop
Summary: In this study, we characterized the electrical and thermoelectric properties of layered WSe2 with thicknesses ranging from 10 to 96 nm at temperatures between 300 and 400 K. By electrostatically gating the devices with an ion gel, we were able to investigate both electron and hole behavior over a wide range of carrier densities. The highest n- and p-type Seebeck coefficients for thin-film WSe2 at room temperature, -500 and 950 μV/K respectively, were obtained in this study. We also highlighted the significance of low substrate thermal conductivity for lateral thermoelectric measurements, which improves the platform for future studies on other nanomaterials.
Article
Chemistry, Multidisciplinary
Jie Zhao, Asir Intisar Khan, Mikhail Y. Efremov, Zichao Ye, Xiangjin Wu, Kangsik Kim, Zonghoon Lee, H. -S. Philip Wong, Eric Pop, Leslie H. Allen
Summary: The phase transition of Sb2Te3/Ge2Sb2Te5 superlattices was studied using nanocalorimetry, providing insights into the thermodynamics of superlattice-based PCM and enabling low-power switching.
Article
Chemistry, Multidisciplinary
Mor Mordechai Dahan, Halid Mulaosmanovic, Or Levit, Stefan Dunkel, Sven Beyer, Eilam Yalon
Summary: The discovery of ferroelectric doped HfO2 enables the development of scalable and CMOS-compatible ferroelectric field-effect transistor (FeFET) technology, which has the potential to meet the demand for fast, low-power, low-cost, and high-density nonvolatile memory and neuromorphic devices. This study demonstrates that a single subnanosecond pulse can fully switch HfO2-based FeFET, revealing the high-speed capabilities of FeFETs and shedding light on the fundamental polarization switching speed limits and kinetics.
Article
Nanoscience & Nanotechnology
Emanuel Ber, Ryan W. Grady, Eric Pop, Eilam Yalon
Summary: Achieving good electrical contacts is a major challenge in devices based on atomically thin 2D semiconductors. This study experimentally examines the classical transmission line model description of contacts to 2D materials and proposes a modification based on an additional lateral resistance component. It finds that the additional lateral resistance component dominates the contact resistance in atomically thin semiconductor devices and is responsible for the back-gate bias and temperature dependence.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Il-Kwon Oh, Asir Intisar Khan, Shengjun Qin, Yujin Lee, H. -S. Philip Wong, Eric Pop, Stacey F. Bent
Summary: This study explores the application of area-selective atomic layer deposition (AS-ALD) technique in the fabrication of RRAM devices and finds that AS-ALD can improve the reliability and accuracy of RRAM, regardless of device size. The application of this technique will contribute to the improvement of other data storage technologies.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Christopher Perez, Aaron J. Mcleod, Michelle E. Chen, Su-In Yi, Sam Vaziri, Ryan Hood, Scott T. Ueda, Xinyu Bao, Mehdi Asheghi, Woosung Park, A. Alec Talin, Suhas Kumar, Eric Pop, Andrew C. Kummel, Kenneth E. Goodson
Summary: Aluminum nitride (AlN) is an electrically insulating material with excellent thermal conductivity. This study demonstrates the deposition of AlN films at low temperatures using sputtering, and analyzes their thermal properties based on grain size and interfacial quality. The results show that varying the partial pressure of reactive N2 can significantly alter the thermal conductivity of the films, and the defect densities can be estimated from the measurements, providing insights for optimizing the thermal engineering of AlN.
Article
Optics
Qitong Li, Jung-Hwan Song, Fenghao Xu, Jorik van de Groep, Jiho Hong, Alwin Daus, Yan Joe Lee, Amalya C. Johnson, Eric Pop, Fang Liu, Mark L. Brongersma
Summary: A general pathway to reduce the detrimental impact of dephasing and non-radiative decay processes in quantum devices is illustrated through photonic design of device electrodes. The design enables large Purcell enhancement, convenient electrical gating, and high modulation efficiencies.
Article
Multidisciplinary Sciences
Joel Martis, Sandhya Susarla, Archith Rayabharam, Cong Su, Timothy Paule, Philipp Pelz, Cassandra Huff, Xintong Xu, Hao-Kun Li, Marc Jaikissoon, Victoria Chen, Eric Pop, Krishna Saraswat, Alex Zettl, Narayana R. Aluru, Ramamoorthy Ramesh, Peter Ercius, Arun Majumdar
Summary: Four-dimensional scanning transmission electron microscopy (4D-STEM) was used to determine the electron charge density in monolayer MoS2 by combining center of mass (CoM) images and annular dark field (ADF) images. The contribution of core electrons and valence electrons to the charge density was evaluated, with the core electrons mainly responsible for the spatial modulation and the valence electrons forming a featureless background. This study highlights the importance of probe shape in interpreting charge densities derived from 4D-STEM and suggests the need for smaller electron probes.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Hon-Loen Sinn, Aravindh Kumar, Eric Pop, Akm Newaz
Summary: Researchers demonstrated a bismuth-1L-MoS2-bismuth device with ohmic electrical contacts and extraordinary optoelectronic properties by suppressing metal-induced gap states (MIGS) at the metal-monolayer MoS2 interface. This overcomes Fermi-level pinning and expands the application range of optoelectronic devices based on 2D transition metal dichalcogenides.
ADVANCED PHOTONICS RESEARCH
(2023)
