2D Materials – Preparation, Properties & Applications: On-Demand Oral Presentations
Sponsored by: TMS Functional Materials Division, TMS: Thin Films and Interfaces Committee
Program Organizers: Nuggehalli Ravindra, New Jersey Institute of Technology; Ramana Chintalapalle, University of Texas at El Paso; Gerald Ferblantier, University of Strasbourg - IUT LP / ICube Laboratory - CNRS; Sufian Abedrabbo, Khalifa University

Monday 8:00 AM
March 14, 2022
Room: Advanced Materials
Location: On-Demand Room

Novel Approach to Wafer Scale Integration of Graphene and h-BN Related 2-D Materials: Jagdish Narayan1; 1North Carolina State University
    The device integration of graphene and reduced graphene oxide (rGO) is impeded by scalability and high temperature (>2000 K) treatment required for high-quality rGO. We present a novel approach for direct laser writing of heavily rGO films by nanosecond laser melting of amorphous carbon, where the quenching from the undercooled melt leads to the formation of large-area rGO films. The laser-irradiated rGO films exhibit electron mobility of 220 cm2/Vs and charge carrier concentration of -1.2x1021/cc at 300 K. Temperature-dependent electrical measurements and Raman spectroscopic investigations suggest low disorder and charge transport via 2D Mott variable range hopping (VRH) between the graphene islands for rGO films. The ultrafast regrowth of rGO creates an atomically sharp interface between n-type rGO and p-type amorphous carbon, resulting in a p–n junction heterojunction diodes This unique laser processing also solves the problems of traps and defects associated with equilibrium-based rGO fabrication methods.

Synthesis and Characterization of MnCo2O4 /GQDs Nano-composites for Super Capacitor Electrodes: Poonam Kharangarh1; 1University of Delhi
    The development of simple and lightweight super-capacitors are considered to be an important part of next-generation energy storage applications due to low cost which shows high performance. The composites related to transition metal oxide with graphene quantum dots are considered to be suitable materials to make an improvement for the electrochemical properties in order to overcome the limitation of super-capacitor applications. In this paper, a facile hydrothermal method was used to prepare GQDs/MnCo2O4 nano-composites with improved conductivity as a promising electrode material to achieve high energy density. The synthesized materials were characterized by Fourier Transform Infra-Red (FT-IR) Spectroscopy, High-Resolution Transmission Electron Microscope (HRTEM), and Powdered X-Ray diffraction (PXRD), and BET. The specific capacitance of the fabricated composite MnCo2O4/GQDs is found to be higher than GQDs due to enhancement in electrical conductivity and diffusion of ions between electrodes and electrolyte (0.1M KOH).

Raman and Transport Characterization of Semiconducting and Superconducting Selenide-based Transition Metal Dichalcogenides: Kishan Jayanand1; Anupama Kaul1; 1University of North Texas
    Transition metal dichalcogenides have captured the interest of the scientific community over the past decade, given their intriguing light-matter interactions in van der Waals membranes, toward a wide variety of platforms. In this regard, NbSe2 shows emergent behaviour, such as charge density waves and superconductivity upon cooling down to cryogenic liquid helium temperatures. Here we report on the use of a superconducting NbSe2 absorber layer for transducing incoming optical radiation into a thermally-driven resistive readout, motivated by the large body of work on traditional transition-edge sensors (TES) in classical bulk superconductors. Through our empirical studies, multilayer NbSe2 crystals were electrically probed, which allowed us to make prototypical demonstrations of the transduction mechanism from the superconducting state to the normal state upon irradiation with several optical sources. Our preliminary studies open up possibilities for exploring NbSe2 in superconducting TES bolometers as radiation detectors.

Rapid Exfoliation of Low-defectivity Graphene in Alkali Lignin Aqueous Media: Claudio Marchi1; Harrison Loh2; Federico Lissandrello1; Konstantinos Sierros2; Luca Magagnin1; 1Politecnico di Milano; 2West Virginia University
    Liquid Phase Exfoliation (LPE) of graphite has been proposed as a scalable and cost-effective method for producing graphene flakes. In this work, alkali lignin is investigated as a non-toxic stabilizer for the rapid (<3h) synthesis of water-dispersible few-layers-graphene (FLG) from commercial acid-intercalated graphite flakes. Time of sonication and lignin-to-graphite ratios are the critical parameters explored for the fine-tuning of the Ultrasonic-Assisted Liquid Phase Exfoliation of the carbonaceous precursor. Raman and UV-Vis spectroscopy are employed as the primary tools for evaluating the quality and nature of the final material. Spectroscopical data processing is conducted according to a range of criteria employed to identify FLG. Morphological investigation of FLG is conducted via SEM and TEM imaging. TGA testing is conducted to assess the amount of residual polymeric stabilizer for ink synthesis optimization. The analysis confirms the absence of significant basal-plane defectivity and the effectiveness of the proposed bio-compatible production route.

Immobilization of Glycine Molecules on Graphene Oxide for Enhanced Piezoelectricity: Sabrina Binte Ashraf1; Emmet O'Reilly2; Shaheen Sarkar2; Syed Tofail2; Fahmida Gulshan1; Md Moniruzzaman1; 1Bangladesh University of Engineering and Technology; 2Bernal Institute, University of Limerick
    Glycine is a simple amino acid that crystallizes in three polymorphs- alpha (α), beta (β), and gamma (γ). Among them, stable γ-polymorphs show piezoelectricity when subjected to limited mechanical force. However, the dipoles become scattered when exposed to large mechanical stress leading to no net polarization and hence no piezoelectricity. Our aim was to stabilize the glycine dipoles by attaching them to the surface of graphene oxide. First, we carboxylated the graphene oxide to increase the carboxyl groups i.e., the reaction sites for attaching glycine molecules. Then to activate the carboxyl groups of graphene oxide and attach the glycine molecules to the carboxylated graphene oxide, we employed EDC-NHS Coupling Reaction. FTIR spectroscopy of the samples is required to examine whether the functionalization was successful whereas SEM of the samples would enable us to observe surface morphology and to distinguish the morphological changes due to all the reactions.