Functional Nanomaterials: Functional Low-Dimensional (0D, 1D, 2D) Materials 2022: Low-Dimensional Electronics & Optoelectronics
Sponsored by: TMS Functional Materials Division, TMS: Nanomaterials Committee
Program Organizers: Michael Cai Wang, University of South Florida; Yong Lin Kong, University of Utah; Sarah Ying Zhong, University of South Florida; Surojit Gupta, University of North Dakota; Nasrin Hooshmand, Georgia Institute of Technology; Woochul Lee, University of Hawaii at Manoa; Min-Kyu Song, Washington State University; Simona Hunyadi Murph, Savannah River National Laboratory; Hagar Labouta, University of Manitoba; Max Anikovskiy, University of Calgary; Patrick Ward, Savannah River National Laboratory

Tuesday 2:30 PM
March 1, 2022
Room: 260B
Location: Anaheim Convention Center

Session Chair: Surojit Gupta, University of North Dakota; Michael Cai Wang, University of South Florida

2:30 PM  Invited
“Smart” Biodegradable Polymer at Nano and Micro Scales for Medical Applications: Thanh Nguyen1; 1University of Connecticut
    The ability to transform medical polymers, commonly used for resorbable surgical sutures, into desired 3D forms/shapes/structures at nano and micro scales with “smart” functions, while sustaining the materials’ excellent biocompatibility and biodegradability, provides significant applications in different biomedical fields, ranging from tissue engineering and controlled drug/vaccine delivery to medical devices. Here, I will present our recent research works to create 3D microstructures of biodegradable polymers for developing single-administered vaccines, and convert the biopolymers into “smart” piezoelectric nanomaterials, which can generate electricity under deformation and vice versa, offering a variety of exciting applications in biodegradable force sensors, tissue-engineering scaffolds and medical transducers.

2:55 PM  
Harnessing Microstructures for Tunable Interference Color: Lauren Zarzar1; 1Penn State University
    A variety of physical phenomena create color, such as selective absorption by dyes, optical dispersion, plasmonic effects, and structural color from light interference. Here, we explore an optical mechanism for creating iridescent structural color that is accessible in microscale geometries. In this mechanism, light traveling by different trajectories of total internal reflection along a concave interface interferes to generate patterns of color. The interference effect is accessible using interfaces with dimensions that are orders of magnitude larger than the wavelength of visible light and is observed in materials as simple as sessile water droplets. We further exploit this phenomenon in more complex systems, including multiphase droplets, solid micro-particles, and 3D patterned surfaces to create colors that are consistent with theoretical predictions. We expect that the design principles and predictive theory outlined here will be of interest for fundamental exploration in optics and application in colloidal paints, films, displays, and sensors.

3:15 PM  
Strain-tunable Optoelectronic Response of Crumpled Graphene/Organic Semiconductor Heterostructure: Zhichao Zhang1; Jin Myung Kim1; Sungwoo Nam1; 1University of Illinois
    Graphene-organic semiconductor heterostructure has drawn attentions in past decade due to the combined advantages from graphene and organic semiconductor, including strong light absorption, high sensitivity, and fast response time. Despite extensive studies thus far, the effects of mechanical strain on the optoelectronic properties of graphene-organic heterostructures remain unexplored. In this work, we report a strain-tunable photodetector prepared by crumpling an ultrathin film of graphene/organic conjugated polymer (PDPP2T-TT-OD) layers on an elastomeric substrate. The crumple structure enabled the film to be stretched up to 300% and exhibited three-fold enhancement in photoresponsivity (10^4 A/W ) compared with a flat heterostructure, attributed to enhanced scattering and reflection of incident light. We also found that strain directions significantly affect the optoelectronic performance of the heterostructure due to modulation of absorptions and charge accumulations in different directions. This work provides a new perspective of strain engineering of graphene-organic semiconductor heterostructures and flexible optoelectronics.

3:35 PM  
Suspended Graphene/PEDOT:PSS Channel for H2 Gas Sensing Fabricated Using Direct-write Functional Fibers: Abiral Regmi1; Noori Na1; Jiyoung Chang1; 1University of Utah
    This work investigates on the hydrogen sensing mechanism of suspended graphene channel precisely patterned to nanoscale regime with near-field electrospinning of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate): Polyethylene oxide (PEDOT: PSS: PEO or PPP) fibers. The PPP fibers can not only act as an etch mask to pattern the suspended graphene channel to desired width but also tune graphene’s electrical property by introducing a doping effect. The suspended graphene/PPP nanoscale channels so produced have higher surface to volume ratio which provides larger area for gas molecules adsorption. Furthermore, the graphene/PPP assembly has shown higher specificity towards H2 gas molecules with respect to graphene or PEDOT:PSS alone. The sensor response is characterized at various conditions such as channel dimensions, temperature, gas concentrations, etc. The ultra-low power consumption capability and miniature size of the sensor make it ideal for sensing application. The results thus promise a simple and low-cost suspended graphene/PPP sensor with enhanced sensitivity.

3:55 PM Break

4:15 PM  
Controlled Synthesis of Gas Sensing Composite Metal/Metal Oxide Graphene-based Nanofibers: Luz Cruz1; Qiurong Shi1; Devis Montroni1; David Kisailus1; Roberto Rivera1; 1University of California, Irvine
    Highly porous 1D nanostructures with controlled size, morphology and high conductivity are beneficial for a number of applications, including highly efficient gas sensors and batteries. Here, we have synthesized composite metal/metal oxide graphene-based nanofibers from an electrospun polymer-metal precursor. Upon heat treatment, metal species diffuse throughout the polymer matrix, nucleate as metal nanoparticles, and subsequently catalyze the formation of crystalline carbon. In this study, we investigate the role of polymer matrix and annealing conditions on metal diffusion, clustering, and growth as well as the subsequent evolution of crystalline carbon. We utilize these parameters to control the size and surface area of metal and metal oxide nanostructures that allow us to tune our material for gas sensing applications. Investigation of the particle growth of these nanostructures within polymer matrix will provide insight to the controlled synthesis and assembly of the nanoparticle constituents and their effect on gas sensing sensitivity.

4:35 PM  Keynote
Structural Evolution and Electrical Conductivity of Polymer Derived Ceramics: Kathy Lu1; Sanjay Kumar1; 1Virginia Polytechnic Institute and State University
    Polymer derived materials are well recognized for their high temperature stability and processing flexibility. It is highly desirable that new functional properties are introduced into polymer derived materials. In this study, flash pyrolysis and conventional pyrolysis are conducted to produce polymer derived SiOC nanocomposites. MXene Ti3C2 has been exfoliated and functionalized to prepare Ti3C2-SiOC composites in order to enable high temperature electrical conductivity. The electrical transport of the synthesized ceramics follows an amorphous semiconductor mechanism. The Ti3C2 phase is preserved up to 1000C in the SiOC matrix, facilitates carbon cluster growth, enhances the SiOC matrix electrical conductivity. The conductivity in the pure SiOC matrix occurs via both free carbon and the SiOC matrix while in the Ti3C2-SiOC samples Ti3C2 enables single percolation pathway. This work is the first to introduce Ti3C2 into the SiOC matrix. These new systems demonstrate important application potentials from room temperature to as high as 1000C.