(1) Earth Abundant Colloidal Nanocrystal Solar Ink and Nanostructured Solar Cells
Colloidal nanocrystals (in particular, non-toxic and earth abundant nanomaterials) with exotic optoelectronic properties are deeply rooted in nanochemistry and material science, will address both fundamental scientific problems and real-world challenges. The synergistic effect between semiconducting and localized surface plasmonic resonance of colloidal nanocrystals enable solution-processing, low-cost and high efficiency nanostructured solar cells (all-inorganic and hybrid inorganic-organic nanomaterials). In this research thrust, we are applying “design-by-synthesis” and “bottom-up” nanochemistry approach to explore new nanomaterials (Such as FeS2 pyrite, Cu2S and so on) and nature intended self-assembly to simultaneously discover, understand and manipulate novel coupling of photonic, electronic and magnetic properties. A unified focus of this project is to develop novel emerging nanomaterials where components and functionalities can be added, tuned or combined in a predictable manner for light harvesting and storage applications.
Figure 1. The 0D, 1D, 2D and 3D colloidal nanocrystals synthesized in the REN group
(2) All Carbon Nanomaterials for Renewable Energy and Spintronic Applications
Zero-, one-, and two-dimensional carbon nanomaterials have all become materials of great importance. While zero-dimensional fullerene and one-dimension SWCNT have been active areas of research for two decades, two-dimensional graphene has only more recently gained attention. It is of considerable interest to investigate the self-assembly of these nanocarbon constituents of different dimensionalities. To date, there have been few studies of the self-assembly of carbon nanomaterials. Novel strategies of self-assembly not only offer solutions to some of the current challenges in solar harvesting, but also lead to understanding of the physical and chemical world, and to discoveries of new phenomena. Our approach is based on the “bottom-up” covalent and noncovalent chemistry that builds upon the self-assembly of carbon nanomaterials, structure-processing-property relationship of 3-D percolation networks composed of carbon electron donor and acceptor phases, and understanding of the operation principle, lifetime and reliability of all carbon heterojunction solar cells, exciton spintronics and photodetectors.
Figure 2. Various nanocarbon materials studied in REN group
(3) Colloidal Magnetic Nanomaterials for High Energy Density Storage and Life Science Research
Colloidal synthesis of monodisperse magnetic hard and soft nanoparticles and nanorods has been successfully applied towards for magnetic energy and data storage, high energy density permanent nanomagnets, life science research and gas production nanocatalysts from hydrocarbons. As they exhibit solution synthesis at a low cost and significantly higher tunability of magnetic properties at the nanoscale, high magnetization (soft phase) and magnetocrystalline anisotropy (hard phase) of magnetic nanoparticles have been attracting attention because they are expected to realize high performance applications. In this project, we are targeting to study the uniform sized magnetic nanoparticles with controllable magnetic properties, in particular, hybridized soft and hard magnetic nanoparticles, for high energy density storage and innovative life science technologies (such as the coupled MRI contrast and hyperthermia agents).
Figure 3. a and b, Exchange coupled soft/hard magnetic nanoparticles with controllable magnetization.
c, Screening of exchange coupled soft/hard magnetic nanoparticle for coupled MRI T2 contrast
agents and hyperthermia treatment.