Seungbae Ahn
Inha University
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Publication
Featured researches published by Seungbae Ahn.
Journal of Materials Chemistry B | 2015
Arunkumar Rengaraj; Yuvaraj Haldorai; Cheol Hwan Kwak; Seungbae Ahn; Ki-Joon Jeon; Seok Hoon Park; Young-Kyu Han; Yun Suk Huh
We demonstrated a non-enzymatic cholesterol sensor based on a nickel oxide (NiO) and high quality graphene composite for the first time. Graphene was grown by a chemical vapor deposition technique (CVD). The nanocomposite was fabricated through the electrodeposition of nickel hydroxide onto the surface of the CVD-grown graphene, which was followed by thermal annealing. The successful formation of the NiO/graphene composite was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The deposition of flower-like NiO onto the graphene surface was confirmed by scanning electron microscopy. Electrochemical analyses were conducted to investigate the characteristics of the sensor during the detection of cholesterol. The sensor showed a high sensitivity of 40.6 mA μM-1 cm-2, a rapid response time of 5 s, and a low detection of limit of 0.13 μM. We also investigated the effects of common interfering substances on the ability of the sensor to detect cholesterol. Furthermore, we successfully determined the cholesterol in a milk sample using the developed sensor. The composite electrode exhibited excellent detection of cholesterol with good reproducibility and long-term stability owing to the combined effects of NiO and graphene.
Scientific Reports | 2015
Hyungtak Seo; Seungbae Ahn; Jinseo Kim; Young-Ahn Lee; Koo-Hyun Chung; Ki-Joon Jeon
The extended application of graphene-based electronic devices requires a bandgap opening in order to realize the targeted device functionality. Since the bandgap tuning of pristine graphene is limited to 360 meV, the chemical modification of graphene is considered essential to achieve a large bandgap opening at the expense of electrical properties degradation. Reduced graphene oxide (RGO) has attracted significant interest for fabricating graphene-based semiconductors since it has several advantages over other forms of chemically modified graphene; such as tunable bandgap opening, decent electrical properties, and easy synthesis. Because of the reduced bonding nature of RGO, the role of metastable oxygen in the RGO matrix is recently highlighted and it may offer emerging ionic devices. In this study, we show that multi-resistivity RGO/n-Si diodes can be obtained by controlling the RGO thickness at a nanometer scale. This is made possible by (1) a metastable lattice-oxygen drift within bulk RGO and (2) electrochemical ambient hydroxyl (OH) formation at the RGO surface. The effect demonstrated in a p-RGO/n-Si heterojunction diode is equivalent to electrochemically driven reversible electronic manipulation and therefore provides an important basis for the application of O bistability in RGO for chemical sensors and electrocatalysis.
ACS Nano | 2015
Myeong-Ho Kim; Young-Ahn Lee; Jinseo Kim; Jucheol Park; Seungbae Ahn; Ki-Joon Jeon; Jeong Won Kim; Duck-Kyun Choi; Hyungtak Seo
The photochemical tunability of the charge-transport mechanism in metal-oxide semiconductors is of great interest since it may offer a facile but effective semiconductor-to-metal transition, which results from photochemically modified electronic structures for various oxide-based device applications. This might provide a feasible hydrogen (H)-radical doping to realize the effectively H-doped metal oxides, which has not been achieved by thermal and ion-implantation technique in a reliable and controllable way. In this study, we report a photochemical conversion of InGaZnO (IGZO) semiconductor to a transparent conductor via hydrogen doping to the local nanocrystallites formed at the IGZO/glass interface at room temperature. In contrast to thermal or ionic hydrogen doping, ultraviolet exposure of the IGZO surface promotes a photochemical reaction with H radical incorporation to surface metal-OH layer formation and bulk H-doping which acts as a tunable and stable highly doped n-type doping channel and turns IGZO to a transparent conductor. This results in the total conversion of carrier conduction property to the level of metallic conduction with sheet resistance of ∼16 Ω/□, room temperature Hall mobility of 11.8 cm(2) V(-1) sec(-1), the carrier concentration at ∼10(20) cm(-3) without any loss of optical transparency. We demonstrated successful applications of photochemically highly n-doped metal oxide via optical dose control to transparent conductor with excellent chemical and optical doping stability.
Carbon | 2014
Heeyoung Jeon; Jingyu Park; Woochool Jang; Hyunjung Kim; Seungbae Ahn; Ki-Joon Jeon; Hyungtak Seo; Hyeongtag Jeon
Sensors and Actuators B-chemical | 2018
Youngho Kim; Duy-Thach Phan; Seungbae Ahn; Ki-Hun Nam; Cheol-Min Park; Ki-Joon Jeon
Advanced Materials | 2016
K. Vijayarangamuthu; Seungbae Ahn; Hyungtak Seo; Sang-Hee Yoon; Cheol-Min Park; Ki-Joon Jeon
Carbon | 2019
Sang Yeon Lee; Jinseo Kim; Seungbae Ahn; Ki-Joon Jeon; Hyungtak Seo
Journal of Nanoscience and Nanotechnology | 2016
Seungbae Ahn; K. Vijayarangamuthu; Ki-Joon Jeon
Advanced Materials | 2016
K. Vijayarangamuthu; Seungbae Ahn; Hyungtak Seo; Sang-Hee Yoon; Cheol-Min Park; Ki-Joon Jeon
한국생물공학회 학술대회 | 2015
Arunkumar Rengaraj; Yuvaraj Haldorai; Cheol Kwak; Seungbae Ahn; Ki-Joon Jeon; Yong-Kyu Han; Yun Suk Huh