Jeonggyu Lee
Seoul National University · 医学
研究室紹介
Professor Jeonggyu Lee's research lab specializes in advanced electronic materials and devices, with a primary focus on resistive random-access memory (RRAM) systems based on titanium oxide (TiOx) and related oxides. The lab investigates fundamental mechanisms of resistive switching, current conduction, and low-frequency noise phenomena, particularly in amorphous and atomic-layer-deposited oxide structures. Key research directions include trap dynamics, oxygen ion migration, and the electrical behavior of nanoscale resistive devices for next-generation non-volatile memory applications. The lab also explores innovative 3D localization algorithms and gas-sensing technologies based on metal-oxide materials.
Research Overview
Research Output Trend
Figures are computed from collected data and may differ slightly.
Selected Papers
15Resistive-switching and current conduction mechanisms have been studied in TiN/Ti/TiOx/HfOx/TiN resistive-switching random access memories (RRAMs). From I-V characteristics and temperature measurement, thermionic emission is found to be the most appropriate mechanism representing the dominant current conduction in all the bias regions and resistance states. Low-frequency noise power spectrum is measured to analyze accurately the conduction mechanism, which corroborates the thermionic-emission. A
Random telegraph noise (RTN) has been studied in amorphous TiOx (α-TiOx) resistance switching random access memories (RRAMs). The RTN having two discrete current levels was observed only in the high-resistance state of the RRAMs. By investigating the bias dependence of capture and emission time constants, we extracted the vertical location of a trap responsible for the RTN in RRAM devices. The trap causing the RTN was found around 5.7 nm below the Ti (top electrode). The trap energy was less by
We investigated the low-frequency noise (LFN) properties of the bipolar switching resistance random access memories (RRAMs) for the first time with amorphous TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> -based RRAM devices. The LFNs are proportional to 1/f for both high-resistance (HRS) and low-resistance states (LRS). The normalized noise in HRS is around an order of magnitude higher than that in LRS. The random telegraph noise (RTN)
The appropriate strategy for enteral feeding remains a matter of debate. We hypothesized that continuous enteral feeding would result in higher rates of achieving target nutrition during the first 7 days compared with intermittent enteral feeding. We conducted an unblinded, single-center, parallel-group, randomized controlled trial involving adult patients admitted to the medical intensive care unit who required mechanical ventilation to determine the efficacy and safety of continuous enteral fe
In this letter, we propose a novel three-dimensional (3D) localization algorithm based on a simple range-based localization approach. The proposed scheme requires distance measurements associated with only three anchor nodes for a 3D location estimation using linear least squares estimation (LLSE). It uses Heron's formula of tetrahedron to calculate the target height and then transforms a two-dimensional location computed by LLSE into a 3D estimated location. Simulation results validate the accu
Gaseous pollutants, including nitrogen oxides, pose a severe threat to ecosystems and human health; therefore, developing reliable gas-sensing systems to detect them is becoming increasingly important. Among the various options, metal-oxide-based gas sensors have attracted attention due to their capability for real-time monitoring and large response. In particular, in the field of materials science, there has been extensive research into controlling the morphological properties of metal oxides.
BACKGROUND: There are limited data available on whether drug-induced hepatotoxicity (DIH) affects the clinical outcomes of tuberculosis (TB) treatment. We explored the effects of DIH on the clinical course and outcomes of pulmonary TB. METHODS: In this retrospective cohort study, we included patients with culture-proven pulmonary TB treated in a tertiary hospital from 2013 to 2016. DIH was defined as proposed by the official American Thoracic Society statement. We compared the clinical outcomes
This work presents experimental contact stiffness measurements for various thin films as well as homogenous materials through pressing a flat punch onto a nominally flat rough surface. These materials are typically used in micro/nano technological applications with thickness of the order of few nanometers. The experimental contact stiffness results are compared with predictions by different statistical rough surface contact models to assess their predictive accuracy for thin-film applications an