Strongly correlated electron materials with reduced dimensions
Research on correlated electron materials enriches our understanding of solid
state physics and offers a route toward novel useful devices. Many unique
properties of strongly correlated electron 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.
Integration of multiple functionalities of correlated electron materials thus
requires controlling and understanding their properties on the single or few domain
level. Specifically, this project involves synthesis of transition metal chalcogenide and oxide
nanostructures, fabrication and characterization of nanodevices, and examining various types of phase
transitions at the nanoscale using scanning probe, optical and in situ scanning and transmission
electron microscopes.
Photovoltaics and thermoelectrics of semiconductors
Theoretical as well as experimental studies have demonstrated the great promise
that semiconductors especially nanostructures hold for energy applications.
We examine photon-carrier and phonon-carrier interactions in semiconductor thin films and nanostructures, targeting
fundamental problems in their photovoltaic and thermoelectric applications. Specifically, we study
charge transfer process between quantum dots for high-efficiency solar cell applications, group III-nitride alloys for
broad-spectrum solar cells, and highly mismatched semiconductor alloys for high-ZT themoelectrics. Our work also heavily involves numerical
modeling of charge behavior and device performance of various photovoltaic and thermoelectric structures. This research is partially in collaboration with the
Solar Energy Materials Research Group at the Lawrence Berkeley National Lab.
