권장연 교수

The agglomeration behavior of Cu and Au films each with a thickness of 5 and 50 nm, deposited on thermally grown SiO2 by dc magnetron sputtering, was investigated with scanning electron microscopy. The size of Cu islands formed by agglomeration increased with increasing annealing temperature. Also, the agglomeration of Cu films seem to follow the grain boundary grooving process. On the other hand, Au islands have an identical size at different annealing temperatures. Au films were observed to ag

Abstract Sensors that detect and discriminate external mechanical forces are a principal component in the development of electronic tactile systems that can mimic the multifunctional properties of human skin. This study demonstrates a pyramid‐plug structure for highly sensitive tactile sensors that enables them to detect pressure, shear force, and torsion. The device is composed of pyramid‐patterned ionic gel inspired by neural mechanoreceptors and engraved electrodes. Based on a pyramid‐plug st

This study examined the effect of gate dielectric materials on the light-induced bias instability of Hf–In–Zn–O (HIZO) transistor. The HfOx and SiNx gated devices suffered from a huge negative threshold voltage (Vth) shift (>11 V) during the application of negative-bias-thermal illumination stress for 3 h. In contrast, the HIZO transistor exhibited much better stability (<2.0 V) in terms of Vth movement under identical stress conditions. Based on the experimental results, we propos

As a means to overcome the limitation of installation space and to promote the utilization of the solar cell in various applications, a transparent thin-film solar cell has been studied by many researchers. To achieve a transparent solar cell, the choice of materials which are transparent enough and showing the photovoltaic property at the same time is the key. Here, we suggest a two-dimensional (2D) p-n heterojunction of WSe₂/MoS₂ and an indium tin oxide electrode to fabri

We investigated the effect of device configuration on the light-induced negative bias thermal instability of gallium indium zinc oxide transistors. The of back-channel-etch (BCE)-type transistors shifted by −3.5 V, and the subthreshold gate swing (SS) increased from 0.88 to 1.38 V/decade after negative bias illumination temperature stress for 3 h. However, etch-stopper-type devices exhibited small shifts of −0.8 V without degradation in the SS value. It is believed that the inferior instability

Two-dimensional (2D) semiconductors can be promising active materials for solar cells due to their advantageous electrical and optical properties, in addition to their ability to form high-quality van der Waals (vdW) heterojunctions using a simple process. Furthermore, the atomically thin nature of these 2D materials allows them to form lightweight and transparent thin-film solar cells. However, strategies appropriate for optimizing their properties have not been extensively studied yet. In this

Abstract Triboelectric nanogenerator technology is one of the most promising technologies with great potential for applications in self‐powered electronics and sensing systems. Herein a simply fabricated, cost‐effective, triboelectric sensor with a roller‐bearing structure which is composed of rollers and electrode is presented. Based on the triboelectric effect, this smart bearing generates the output electrical signals in response to rotation movement or displacement of an object mounted with

The electrical stability of molybdenum disulfide (MoS2) transistors is crucial for their use in various applications. However, it is tricky to evaluate the inherent stability of MoS2 transistors because it is highly dependent on environmental conditions during measurement such as humidity, light, and electrical factors. We studied the threshold voltage instability under negative bias stress at a variety of temperatures in a vacuum and in the dark to eliminate any environmental effects. In partic

The development of a highly sensitive artificial mechanotransducer that mimics the tactile sensing features of human skin has been a big challenge in electronic skin research. Here, we demonstrate an ultrasensitive, low-power oxide transistor-based mechanotransducer modulated by microstructured, deformable ionic dielectrics, which is consistently sensitive to a wide range of pressures from 1 to 50 kPa. To this end, we designed a viscoporoelastic and ionic thermoplastic polyurethane (i-TPU) with

Transition metal dichalcogenides (TMDCs) have recently been studied using various synthesis methods, such as chemical vapor deposition for large-scale production. Despite the realization of large-scale production with high material quality, a range of approaches have been made to solve the patterning issue of TMDCs focusing on the application of integrated devices; however, patterning is still under study to accurately represent nanoscale-sized patterns, as well as the desired positions and shap

Black phosphorus (BP) has shown great potential as a semiconductor material beyond graphene and MoS₂ because of its intrinsic band gap and high mobility. Moreover, the biocompatibility of the final biodegradation products of BP has led to extensive research on biomedical applications. Herein, physically transient field-effect transistors (FETs) based on black phosphorus have been demonstrated using peptide insulator as a gate dielectric layer. The fabricated devices show high hole mob