- 2002 Seoul National University (Ph.D.-Physics: GaN LED devices & ultrafast phenomena)
- 1997 Seoul National University (M.S.-Physics: THz devices & characterization)
- 1995 Seoul National University (B.S.-Physics)
- 2007 ~ Present, Faculty, School of Elec. Eng. & Com. Sci., GIST.
- 2014 ~ 2015, Visiting Prof., Caltech, USA.
- 2013 ~ Present, Science & Creativity Ambassador” designated by Korean Foundation for the Advancement of Science and Creativity.
- 2012 ~ Present, selected into Marquis who’s who.
- 2004 ~ 2007, Assistant Scientist, Univ. of Florida, USA.
- 2003 ~ 2004, Visiting Postdoctoral Associate (as part of an army service), Seoul Nat’l Univ.
- 2002 ~ 2003, Postdoctoral Associate, National High Magnetic Field Lab., USA.
- 2001 ~ Present, Awards from 2001 CLEO-PR (Conference Travel Award for Students), 2005 NSF research highlight from NHMFL, 2011 KPS/2010 OSK/2012 Int. Conf. on Nano Sci. & Tech./2015 CLEO-PR(Best conf. papers), 2016 GIST research excellence & 10 most representative technologies.
- Heat-smart optoelectronics: Heat dissipation engineering in semiconductor chips.
- Thermoelectricity using semiconductors: Waste heat recovery into electricity.
- Quantum phononics: Quantized thermal conduction and terahertz energy transport.
- Thermal metamaterials: Design, growth, and characterizations
- Electro-phononics for thermal circuitry
- Integration of electronics, photonics, and phononics.
- In recent decades, major technological innovations such as the transistors and LEDs have been based on the manipulations of electrons and photons. Phonons, or quanta of atomic vibrations, are responsible for heat conduction but remain poorly understood, and this lack of understanding impedes efforts to improve device performance such as speed, lifetime, and quantum yields. We have accumulated intensive research results and research know-how in the field of compound semiconductors and optoelectronics, and have built infrastructures such as clean rooms, cutting-edge experimental equipment and related research expertise. However, the separate manipulation of electrons or photons has reached technological saturation as revealed in, e.g., the limitation of Moore’s Law since the 2010’s.We, HOPE (Heat-smart Optoelectronics & Phonon Engineering), have proposed and pioneered new methodologies for integrated manipulations of electrons, photons, and phonons, to further enhance the efficiency and lifetime of semiconductor devices and systems. Especially, we note the heat-related technology follows the traditional diffusion-based thermal conduction and particle-oriented statistics; In this case, phonons (or, heat carriers in solids) could be treated well only at large scale, while in the nanoscale, phonon engineering was not only required to have new theoretical formulations according to wavy nature, but also functional phonoic materials for heat manipulation must be developed. For such purposes, we innovate the concept of integrated controllability beyond the conventionally separated electronics, photonics, and phononics to further utilize thermal properties and pioneer revolutionary heat manipulations.
In terms of communication, the 10-fold improvement in speed has been attained in 10-year cycle in most of applications. In the case of wireless communications, carriers of THz band, exceeding the saturated GHz band is the core part for the prospective applications. We note the phonon frequency ranges from 0.1 to 100 THz in semiconductors, thus, could be utilized for new information processing techniques. The related concepts are nanoscale phonon communications, quantum computing based on coherent phonon wave packets, thermal circuitry using phonon diodes/transistors/gates and phononics-photonics integrations.
From a material point of view, we pursue i) a systematic understanding of the state of electrons, photons, and phonons in semiconductors, ii) the use of nanoscale materials, including phonon-metamaterials, graphene, transition-metal dichalcogenides, and other one-atomic-thick materials (Iii) research on new electro-phononic devices such as diodes, transistors, logic circuits, and frequency modulation using phonons, and iv) conversion of waste heat to the electricity.
The purpose of these HOPE-proposed works is thus impactful both in engineering and scientific viewpoints; to newly integrate engineered heat manipulation structures into optoelectronics, and to understand the microscopic heat transport mechanisms in nanoscale heat dissipation materials, thermoelectricity, and the artificially designed thermal metamaterials for next-generation semiconductor devices.
For more details, visit http://hope.gist.ac.kr/