2D Materials: Preparation, Properties, Modeling & Applications: Modeling & Simulation
Sponsored by: TMS Functional Materials Division, TMS: Thin Films and Interfaces Committee
Program Organizers: Nuggehalli Ravindra, New Jersey Institute of Technology; Madan Dubey, US Army Research Laboratory; Sufian Abedrabbo, Khalifa University; Hesam Askari, University Of Rochester; Gerald Ferblantier, University of Strasbourg - IUT LP / ICube Laboratory - CNRS; Ramana Chintalapalle, University of Texas at El Paso; Joshua Young, New Jersey Institute of Technology; Adele Carrado, University of Strasbourg; Karine Mougin, Cnrs, Is2m; Heinz Palkowski, Clausthal University of Technology
Wednesday 8:30 AM
March 22, 2023
Room: Aqua AB
Location: Hilton
Session Chair: Joshua Young, New Jersey Institute of Technology; Karine Mougin, CNRS - IS2M
8:30 AM Introductory Comments
8:35 AM Invited
A New Experimentally Guided Computational Database for 2D Metal-organic Frameworks: Zeyu Zhang1; Dylan Valente1; Yuliang Shi1; Dil Limbu1; Farnaz Shakib1; 1New Jersey Institute of Technology
Metal-organic frameworks (MOFs) are nano-porous architectures with applications in gas storage and separation, catalysis, and water treatment. Electrically conductive two-dimensional (2D) MOFs, with their ideal architecture, promise unprecedented breakthroughs in producing high-performance and cost-effective batteries, semiconductors, and supercapacitors. Here, we facilitate research in this area by creating a comprehensive database of different classes of 2D MOFs which allows screening them for desired applications using different high-throughput screening techniques. To build our database, we first performed a thorough literature survey and summarized all reports, either experimental or theoretical, on electrically conductive 2D MOFs. We then developed an in-house structural creation software, coined structural creation python package, or SCP2. More than a thousand MOFs are created by SCP2 and optimized at DFT level. The optimized structures are classified based on their structural features, thermodynamic stability and electrical properties to provide guidelines for the right choice of a 2D MOF for designing purposes
9:00 AM Invited
Carrier Mobility in 2D Semiconductors: Insights and Predictions from First Principles: Yuanyue Liu1; 1University of Texas at Austin
2D semiconductors are promising candidates for future electronics, while they often have a low carrier mobility at room temperature. I will present our works to understand the origin of low carrier mobility, as well as the discovery of higher-mobility 2D semiconductors. By developing and applying first-principles methods, we calculate the scatterings from phonons [1-3] and defects, and provide the insights into the mobility-limiting bottlenecks and design principles to overcome the limitation. Using these principles, we computationally screen the 2D materials database, and discover a number of new semiconductors with very high carrier mobility, which may simulate experimental realization. [1] L. Cheng, C. Zhang, Y. Liu*, Phys. Rev. Lett. 2020, DOI: 10.1103/PhysRevLett.125.177701 [2] L. Cheng, C. Zhang, Y. Liu*, J. Am. Chem. Soc., 2019, DOI: 10.1021/jacs.9b05923 [3] L. Cheng, Y. Liu*, J. Am. Chem. Soc., 2018, 140, 17895-17900
9:25 AM Invited
Modeling of Optoelectronic Properties of Charged Defects, Dopants, and Complexes in 2D Materials: Richard Hennig1; Anne Tan2; Biswas Rijal1; Christoph Freysoldt3; 1University of Florida; 2Nanyang Technological University; 3Max Planck Institut für Eisenforschung
Realizing the potential of 2D materials for electronic and quantum applications requires understanding the effects of defects, dopants, and impurities on their electronic and optical properties. We perform density functional theory (DFT) calculations to accurately compute formation energies, charge transition levels, and electronic properties of dopants, defects, and complexes in the technologically significant 2D semiconductor materials focusing on the metal chalcogenides MoS2, WSe2, SnS, and phosphorene. We utilize a correction scheme to ensure appropriate electrostatic boundary conditions for charged defects in 2D materials. Some defects induce structural distortions, e.g., Jahn-Teller and other lattice reconstructions, altering electronic properties. We identify dopants that bind with intrinsic defects to form complexes, passivating the dopants and rendering them less effective. For SnS and phosphorene, large atomic relaxations during charge transitions result in significant Stokes shifts, as large as 1 eV, which may provide opportunities for increased efficiency in optoelectronic applications.
9:50 AM Break
10:05 AM
Modelling and Validation of Multiple Bubbles Dynamics and Their Effect on Liquid Phase Exfoliation of 2D Materials: Ling Qin1; Jiawei Mi1; 1University of Hull
Ultrasound processing of materials often involves the application of ultrasound of different intensities into a multiphase mixture of liquid and solid phases. There are intensive interactions between the liquid and solid phases as well as the cavitation bubbles due to ultrasound. To understand the transient, multiscale and multiphase interactions fully, we have developed bubble dynamic models based on the Volume of Fluid (VOF) and Continuous Surface Force (CSF) methods. The model is able to simulate bubble oscillation, implosion, and coalescence dynamics under ultrasound. The model has been validated via comprehensive image data collected by ultrafast synchrotron X-ray imaging. Here, we focus on studying bubble interactions with solid phases and the associated stresses due to bubbles oscillation and implosion as well as the effect of multiple bubbles coalescence. The chain effect of multi bubble implosion on the phase exfoliation of 2D materials was reported for the first time.
10:25 AM
Monolayer-like Lattice Dynamics in Bulk WSe2: Qingan Cai1; Chen Li1; Qiyang Sun1; Ayman Said2; Bin Wei3; 1University of California-Riverside; 2Argonne National Laboratory ; 3Henan Polytechnic University
Understanding the microscopic lattice dynamics is essential for regulating the thermal properties in two-dimensional layered materials. In transition metal dichalcogenides, the layered structures result in different but closely related phonon dispersions between monolayer and bulk. Here, by combining inelastic X-ray scattering and first-principles calculations, the lattice dynamics of tungsten diselenide (WSe2) was investigated comprehensively, and a monolayer-like lattice dynamics in the bulk WSe2 was revealed. We performed the first measurements of the temperature-dependent phonon dispersions and the mode Grüneisen parameters of bulk WSe2, which are found to be in better agreement with the calculations on the monolayer system than those of the bulk. This observation indicates that lattice dynamics in bulk WSe2 hold the characterization of monolayers. The result provides valuable insights into the thermal properties of WSe2-based devices.
10:45 AM
Phase Field Modeling of Localized Thermal Oxidation of Monolayer WS2: Maryam Kazemzadeh-Atoufi1; Ye Fan2; Ryo Mizuta2; Stephan Hofmann2; Peter Voorhees1; 1Northwestern University; 2University of Cambridge
Oxidation at the atomic level has gained interest given the increasing and rapid development of low-dimensional materials for a variety of device applications. We investigate the growth of corrosion pits in single-crystalline, monolayer domains of WS2 during thermal oxidation by localized injection of air at temperatures ranging from 450°C to 680°C. The experimentally measured growth kinetics of the individual pit areas undergo a transition from linear to quadratic time-dependence with increasing temperature. We use a quantitative multi-phase field model to investigate the mechanism driving this transition. The model simulates growth of the etch pits by diffusion and a flux of oxygen atoms into the surface. The growth rate depends on the relative strength of the diffusion coefficient compared to the flux of oxygen atoms. At low temperatures, the growth of the etch pits is diffusion-limited, while at high temperatures the growth rate is controlled by the rate of atom arrival.
11:05 AM
Theory of the Mechanical Exfoliation of 2D Materials: Haoye Sun1; Hannah Gramling1; Vu Nguyen1; Ali Javey1; Hayden Taylor1; Joel Ager1; Daryl Chrzan1; 1University of California
Mechanical exfoliation is typically not considered to be feasible as a route to manufacturing devices at scale, as the results films are often irregularly shaped, and not positioned with precision. Recently, we have demonstrated that mechanical exfoliation can be used as a reliable means to assemble ordered arrays of van der Waals heterostructures. Here, the theory underlying that process is presented. Using both atomic scale and continuum models, we identify the underlying physics governing mechanical exfoliation of 2D materials, and show how the effects of strain, twist and temperature influence the process. The model explains how a thin metallic layer can assist in the exfoliation process, and also suggests that yields can be improved if exfoliation is carried out at low temperatures. This work is supported by NSF and by DOE, Office of Basic Energy Sciences.
11:25 AM
Tunable Adsorption and Catalysis on Two Dimensional Ferroelectric Materials and Heterostructures: Mo Li1; Joshua Young1; 1New Jersey Institute of Technology
Two dimensional ferroelectric materials display a switchable spontaneous electric polarization in one or few monolayers. Interestingly, switching the polarization can change the surface properties, providing a route to overcoming the Sabatier principle. We first show that the surface of the ferroelectric MXene Y2CO2 with a vacancy can preferentially adsorb CO2 or CO depending on if the surface is poled up or poled down. We then extend that by investigating the reduction of CO2 to CO, formic acid, and methane, and find that the stability of intermediates and final products can be also changed by switching the direction of the polarization. Second, we interface singe transition metal atom and dimer doped graphene with ferroelectric In2Se3; by switching the In2Se3 layer, the adsorptive properties of the metal-doped graphene layer can also be altered, leading to selective adsorption and catalysis. This is a unique route to preferential adsorption and product selectivity in catalysis.