he Applied Physics/Engineering Division has long been the premier gathering place for the global community of device physicists and engineers, material scientists, and surface analysts. The division provides a forum for research in nanotechnology, optoelectronics, magneto-optics, renewable energy generation and storage and thin film electronic devices in general. The research including material synthesis, device engineering, and characterization of thin film surfaces and interfaces is covered as well. Furthermore, the 2D materials such as graphene, and transition metal dichalcogenides and their application in optoelectronic devices, sensing, energy storage, quantum computing, etc. are discussed. In addition, the session will include bio-medical devices and applications related to high frequency communication in consumer electronics, EVs, and aviation. The division broadly includes the following topics:
- Solar cells, batteries, thermoelectric devices and supercapacitors
- Catalysis, fuel cells and water splitting
- Bio-batteries, bio-solar cells and microbial fuel cells
- Nanomaterial synthesis, 2D materials and corresponding devices
- Light emitting diodes and transistors
- Materials for quantum information science
- Biomedical devices and wearables
- Antenna, amplifiers, passive devices, etc. for high speed communication
Invited Speaker/s
Title:
Pseudocapacitive Manganese Oxide/Carbon Nanotubes Electrodes for High Capacity Supercapacitors
Abstract:
In recent years, supercapacitors are fetching limelight due to their unique electrochemical properties that make these systems offer higher energy density, higher power density and longer cycle-life. Supercapacitors can be considered a device between batteries and dielectric capacitors as they combine the properties of both capacitors (which can deliver energy in very short time) and batteries (which can store high amount of energy). Hybrid supercapacitors use a composite of high electronic conductivity carbonaceous materials and transition metal oxides in order to greatly improve the electrochemical performance. In this project, carbon nanotubes (CNTs) are used as the electric double layer capacitor (EDLC) type material combined with the pseudocapacitive nature of manganese oxide (MnO2). A simple and highly efficient electrodeposition method was used to produce high surface area nanoflower like hierarchical manganese oxide on the CNTs grown on a flexible carbon fabric (CF) substrate. This binder-free nanostructured MnO2/CNT composite electrode material exhibited an excellent electrochemical energy storage capability with high specific capacitance of 219 F g-1, an areal capacitance of 1.5 F/cm2, and ~86% capacity retention after 2000 cycles. Such enhanced performance comes from the combined effect of double layer charge storage mechanism of the CNTs and the pseudocapacitive nature of the manganese oxides. In this talk, some basics of supercapacitor charge storage mechanism and how the physical properties of the substrate such as microstructure, surface area, and pore size affected the nature of deposited MnO2 and the corresponding device performance will be presented.
Please look below for detailed schedule.
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Abstract Number: ANPA2023-N0001 Presenting Author: Sujan Bhandari Presenter's Affiliation: Central Department of Physics Location: Central Department of Physics, T.U., Nepal Show/Hide Abstract Phosporic Acid (H_3PO_4) can be used to activate different precursors and produce activated carbon(AC) ,a porous material with high adsorption capacity and surface area. This research compares how AC is made using different locally available precursors namely Amla seeds and Harro seeds. We look at how carbonization temperature affects the AC yield, surface area, pore structure and electrochemical properties. We use different methods to analyze the AC samples such as scanning electron microscopy, Fourier transform infrared spectroscopy and cyclic voltammetry. We show that the best conditions for making AC depends on the type of precursor. We also talk about the use of AC for storing energy.
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Abstract Number: ANPA2023-N0002 Presenting Author: Keshab Pandey Presenter's Affiliation: Department of Physics, Daegu University, Gyeongsan 38453, South Korea Title: Modification of Tungsten Disulfide for Electrochemical Energy Storage and Conversion Location: Central Department of Physics, T.U., Nepal Show/Hide Abstract Tungsten disulfide (WS2) is modified, by using ambient solution plasma, for electrochemical energy applications which are hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and flexible supercapacitor applications. Herein, the effect of time-dependent plasma treatment on WS2 is investigated, resulting that the optimum time (60 min) shows the best performances of low overpotential of -0.19 V at -10 mA cm-2 and 0.21 V at 10 mA cm-2 with the corresponding Tafel slopes of 113 mV dec-1 and 124 mV dec-1 for HER and OER, respectively. In addition, a high specific capacitance of 157.5 F g-1 at 1 A g-1 with an energy density of 14 Wh kg-1 and power density of 400 W kg-1 for the flexible supercapacitor is obtained. Reliable flexibility with high specific capacitance retention (94.0%) and coulombic efficiency (89.5%) after 5,000 cycles are also demonstrated. The increased electrochemically active surface area, lower impedance, and the phase transition from 2H to 1T, compared to the precursor WS2, are ascribed to the better HER, OER, and supercapacitor performance.
Keywords: Tungsten disulfide; ambient solution plasma; hydrogen evolution reaction; oxygen evolution reaction; supercapacitor.
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Abstract Number: ANPA2023-N0004 Presenting Author: Bibandhan Poudyal Presenter's Affiliation: University of Rochester Location: Florida International University, FL, USA Show/Hide Abstract Accessibility in general is an abstract concept to quantify. However, several researchers have attempted to quantify accessibility to amenities (city structures) either using spatial heterogeneity—diversity and density of amenities in space or looking for topological (street) connectivity of those amenities. Only few have used the correlation between spatial diversity and topological connectivity of urban amenities to understand the accessibility. We develop a simple, principled, and flexible framework to characterize the directness of accessibility among heterogeneous amenities in a city, which we call the Class First Passage Difference (CFPD). The CFPD quantifies the excess travel distance incurred when using the street network to route between different pairs of amenity types, summarizing both the spatial and topological correlations among amenities in a city. Our measure showed significant correlation with different prosperity and accessibility indicators when compared with the null model—random distribution of amenities keeping their frequency constant. Our measure provides a principled, interpretable and complementary perspective to existing measures of urban accessibility.
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Abstract Number: ANPA2023-N0003 Presenting Author: Trailokya Bhattarai Presenter's Affiliation: UNC Charlotte Location: Florida International University, FL, USA Show/Hide Abstract Title: Cost-effective III-Nitride Quantum Wells-Based UV-C LEDs for Microbial Disinfection—Wavelength Optimization and Solar Cell Integration
Trailokya Bhattarai1, M. Yasin Akhtar Raja2, and Abasifreke Ebong1
1Department of Electrical & Computer Engineering and 2Center for Optoelectronics & Optical Communication, University of North Carolina Charlotte, NC 28223
Corresponding Email: tbhattar@uncc.edu
Abstract:
UV-C is known to be the most effective category of UV- Light Emitting Diodes (LEDs) for deactivating microbes and viruses. This study focuses on the design and testing of a cost-effective III-Nitride quantum wells-based UV-C LEDs in the spectral range (200 nm < λ ˂ 300 nm) for microbial disinfection. Our research objective is to determine the most effective UV-LED wavelength, dose, and exposure time for deactivating a variety of microorganisms and to develop a cutting-edge UV LED disinfection system powered by solar energy. Four prototypes of UV-C LEDs sub-systems with wavelengths range of 255 nm, 265 nm, 275 nm, and 285 nm are designed and are under rigorous testing for effectiveness. This study explores the effects of UV-C exposure on the DNA/RNA of the pathogens before and after exposure to the UV dose. The qPCR/Cell culture methods are applied for quantitative as well as qualitative analysis of the effectiveness of UV irradiation on the deactivation of microbes. Preliminary results for bacteriophages, Phi6 and MS2 are presented, and further testing on other microbes is underway. The results of this research could provide valuable insights for the development of sustainable, efficient, and cost-effective solutions to fight against the spread of infectious diseases. By developing cost-effective and efficient solar-powered UV-C LED systems, the study offers a potential solution for deactivating pathogens in a sustainable and energy-efficient manner. Preliminary results and findings will be presented with the scope of future work.
Keywords: Quantum Wells, UV-C LEDs, microbial disinfection, Cell Culture/qPCR, UV dose, solar-powered UV LED
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Abstract Number: ANPA2023-N0005 Presenting Author: Tara Dhakal (Invited) Presenter's Affiliation: Electrical and Computer Engineering Department Binghamton University, State University of New York, NY Location: Virtual Presentation Show/Hide Abstract In recent years, supercapacitors are fetching limelight due to their unique electrochemical properties that make these systems offer higher energy density, higher power density and longer cycle-life. Supercapacitors can be considered a device between batteries and dielectric capacitors as they combine the properties of both capacitors (which can deliver energy in very short time) and batteries (which can store high amount of energy). Hybrid supercapacitors use a composite of high electronic conductivity carbonaceous materials and transition metal oxides in order to greatly improve the electrochemical performance. In this project, carbon nanotubes (CNTs) are used as the electric double layer capacitor (EDLC) type material combined with the pseudocapacitive nature of manganese oxide (MnO2). A simple and highly efficient electrodeposition method was used to produce high surface area nanoflower like hierarchical manganese oxide on the CNTs grown on a flexible carbon fabric (CF) substrate. This binder-free nanostructured MnO2/CNT composite electrode material exhibited an excellent electrochemical energy storage capability with high specific capacitance of 219 F g-1, an areal capacitance of 1.5 F/cm2, and ~86% capacity retention after 2000 cycles. Such enhanced performance comes from the combined effect of double layer charge storage mechanism of the CNTs and the pseudocapacitive nature of the manganese oxides. In this talk, some basics of supercapacitor charge storage mechanism and how the physical properties of the substrate such as microstructure, surface area, and pore size affected the nature of deposited MnO2 and the corresponding device performance will be presented.
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