Research
Next-generation electronics enabled by
the physical uniqueness of low-dimensional electron systems!
Check out our lab poster: click here!
나노 구조 혹은 저차원에서 전자가 가지는 물리적 특이성을 이용하여
전자 소자의 성능을 개선하거나 새로운 구동 원리의 반도체 소자를 개발하는 연구를 수행중입니다.
Electrical Characterization of High-mobility Emerging Semiconductors:
Transport spectroscopy; measurements of band structure information
Electron transport and quantum phenomena in semiconductor nanostructures
Nanostructure Electronic/Optoelectronic Device Applications:
High mobility transistors, steep-slope transistors, low-power tunneling electronics, multi-valued logics, electronic sensors, contact property optimization etc.
Vertical Electron Transport in Heterostructures Based on van der Waals Materials:
Dynamic modulation of band alignment and tunneling properties
Ballistic transport along the vertical direction in van der Waals materials
Band modulation by Morie-induced superlattices
TRANSPORT SPECTROSCOPY:
We have a special technique to measure electron energy (Fermi energy) as a function of electron density. The measured electron energy vs density data provide band gap, effective mass, and Fermi velocity, which are important fundamental electronic properties and critical to design of diverse electronic and optical applications. We also do manipulating electronic structure of materials for practical purposes, and probing the reconstructed electronic structure.
NOVEL QUANTUM STATES:
We are interested in various quantum phenomena such as quantum Hall effect and topological/quantum spin Hall states in two-dimensional materials. In such nanoscale materials due to the reduced dimensionality quantum effect can be pronounced. Using our non-local Fermi energy measurement technique we are capable of direct probing of energy of such quantum states. We design novel condensed matter systems, study new quantum phenomena, and explore practical nanoelectronics using emerging nanoscale materials and physics. This research includes developing new method of nano fabrication and precise characterization techniques.
QUANTUM TUNNELING and TUNNELING ELECTRONICS:
Two-dimensional (van der Waals) materials allow us to develop atomically thin nano devices, in contrast to conventional bulk materials. There are diverse choices of two-dimensional materials and their combinations, which can offer multiple functionalities. Double layer electron systems separated by an atomically thin barrier can show a variety of interesting physical phenomena including resonant quantum tunneling and unique interlayer interaction effects. We are developing new types of low-power high-speed nanoscale tunneling devices.
DYNAMICALLY TUNABLE PLASMONICS:
Plasmons are collective charge density oscillations in (conventionally) metals in response to incident electromagnetic field (light). Electrically tunable plasmonics is obviously more favorable then static devices. However, it cannot be easily achieved because most of conventional plasmonic materials are noble metals, of which Fermi energy is barely adjustable. In contrast, Fermi energy and corresponding plasmonic behavior of graphene are tunable using electrostatic gating. Plasmonics using two-dimensional materials (especially graphene) is thus now getting attraction, but not many systems have been suggested nor thoroughly tested. We aim to create new plasmonic heterostructures based on two-dimensional materials, where we can manipulate how much and where to populate electrons, and gain a vast plasmonic tunability.
