The unique properties of carbon and silicon-based nanomaterials, including their mechanical, electronic, thermal, and optical properties, have led to rapid advancements in nanotechnology. However, producing large-scale low-dimensional nanomaterials with desired structures remains challenging due to difficulties in controlling atomic-scale physical and chemical reactions during synthesis and a lack of understanding of the underlying mechanisms. Our group is dedicated to developing novel synthesis processes for nanocarbon materials, such as nanotubes, graphene, and nanoporous graphitic film, using chemical vapor deposition and nano-template synthesis methods. We aim to apply these extreme nanocarbon materials in multifunctional energy storage systems and high-performance, low-power nano/microsensors. Additionally, we are investigating a novel catalyst-free chemical vapor etching process to synthesize ultra-high-density and vertically aligned sub-5nm silicon nanowires directly on Si wafers. These ultra-narrow nanowires show an unusual lattice reduction of up to 20% and a direct optical bandgap of 4.16 eV and quasi-particle bandgap of 4.75 eV, indicating significant phonon and electronic confinement for their potential uses in nanoelectronics, optoelectronics, and energy systems.

Nanocarbon networks, such as nanotubes and graphene, possess exceptional electronic, thermal, and mechanical properties, making them ideal for high-performance multifunctional materials. However, van der Waals connected networks reduce these benefits. Our group is investigating a novel carbon nanostructure and its network engineering process using external energies such as pulsed electric current and laser-induced shockwaves to address this. These processes enable us to tailor carbon-carbon sp2 molecular junctions between assembled nanocarbon structures, resulting in continuous novel sp2 molecular networks (ex: graphenenic nanoribbon) with substantial mechanical, thermal, and electrical property improvements. We believe that these molecularly engineered nanocarbon networks could have broader applications, particularly in strong and highly conductive multifunctional film and fibers for lightweight and high-performance composites, electronics, and energy storage device electrodes.

Scaling up the fabrication of nano, micro, and macroscopic devices and systems with low-dimensional nanomaterials allows for high-performance and multifunctional devices in a broad range of applications. Our group investigates nanomanufacturing processes, such as template-guided fluidic assembly, direct printing transfer, and device integration techniques to fabricate 1-3D dimensional nano/microarchitectures of extreme nanocarbon and silicon nanostructures on various substrates, including Si, SiO2, metals, polymers, and nano/micro-patterned flexible polymer surfaces. Using these unprecedented nanostructured architectures, our group is also studying and developing high-performance and ultra-low-power radiation, ion, and chemical sensors, light-emitting devices, photo-detectors, flexible electrical interconnects, and flexible and transparent energy storage devices.