: Multiscale defects in 2D materials
|
서준기 교수 울산과학기술원 Semiconductors are core elements for modern technology. In this talk, I will present research highlights on functioning nanoscale semiconductors, mainly layered two-dimensional crystals, with multi-dimensional imperfections; atomic removal (point defects), substitution (doping) and crystal deformation (topological defects). I will first introduce a defect engineering method for thermal energy applications of semiconductors, combined with high-energy ion irradiation that allows to modulate the density of point defects under high controllability. This method is successfully demonstrated forhigh-performance thermoelectrics by decoupling the undesired interdependence among three key transport parameters: electrical conductivity, thermopower and thermal conductivity. I will then report how substitutional chemical doping can drastically alter the crystal structure and optical properties of atomically-thin host materials where the electron wavefunction is tightly confined thereby strongly interacting with the foreign atoms. Finally, a new paradigm of geometry/topography-property relationship is explored as an innovative method to encode the desirable properties at growth level.. |