The Park group research focuses on the science and technology of nanomaterials. Our research is multidisciplinary; the group includes researchers with diverse backgrounds, including chemistry, physics, material science, and electrical engineering.
Atomically thin circuitry
One main research goal is to build atomically-thin integrated circuitry. In order to build atomically thin integrated circuitry, we develop advanced growth, characterization and device fabrication methods for 2D layered materials, which include electrically conducting graphene, insulating hBN and semiconducting transition metal dichalcogenides. For example, we reported the atom-resolution imaging of individual grain boundaries in graphene using transmission electron microscope (TEM) (Nature, 2011) and investigated their electrical properties (Science, 2012). We also developed a method for producing atomically thin lateral heterojuctions within individual 2D films (Nature, 2012), and reported the metal-organic chemical vapor deposition (MOCVD) growth of wafer-scale three-atom-thick semiconductor films with high mobility (Nature, 2015). Our results enable the fabrication of electrically isolated active and passive elements embedded in continuous, one- and few-atom-thick sheets, which could further be manipulated and stacked to form complex devices at the ultimate thickness limit.
Nanostructure-based electronics and optoelectronics
Another research goal is to explore novel electrical, optical, and optoelectronic properties of low-dimensional nanostructures, which will allow the development of advanced devices, including highly efficient solar cells, ultrasensitive infrared bolometric detectors, and novel valleytronic and spintronic devices. In the past, we reported multiple exciton generation (Science, 2009*), optical intertube coupling (Nature Nanotech. 2011) and photothermal current microscopy (Nature Nanotech. 2009) in carbon nanotubes, supercollision cooling (Nature Phys., 2013*) and giant circular dichroism (Nature Nanotech. 2016) in graphene, and the valley Hall effect in MoS2 transistors (Science,2014*). (*collaboration with the McEuen group at Cornell)