Research on functional and correlated electron materials enriches our understanding of solid state physics and enables new applications. Many unique properties of these materials originate from the competition of different degrees of freedom, which usually results in complex phase diagrams and stabilizes multiple phase coexistence at the sub-micron scale. Utilization of these materials thus requires controlling and understanding their properties on the single or few domain level. Specifically, this research thrust involves synthesis of transition metal chalcogenide and oxide nanostructures, fabrication and characterization of nanodevices, and examinination of various types of phase transitions at the nanoscale using scanning probe, optical and in situ tools.
Energy applications of electronic materials
We examine photon-carrier and phonon-carrier interactions in electronic materials in the form of thin films and nanostructures, targeting fundamental problems in their photovoltaic, infrared and thermal/thermoelectric applications. Specifically, we study semiconductor alloys for broad-spectrum photovoltaics, and phase change materials for infrared, photonic and thermal/thermoelectric technologies. We are also officially a part of the Electronic Materials Program in LBNL.
Point defects in electronic materials
We have strong research interest and efforts in the behavior of point defects in electronic materials especially two-dimensional materials. Point defects (e.g., vacancies, interstitials, isotopes, antisites) in some scenarios largely dominate properties of electronic materials, and this becomes especially important for low-dimensional materials. We control, identify, quantify, evaluate and mitigate point defects in various types of electronic materials for fundamental understanding of their materials physics.
Research Highlights and Gallery
Giant isotope effect of thermal conduction in silicon nanowires, Phys. Rev. Lett., 128, 085901 (2022).