| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | E. 환경/센서 재료 분과 |
| 제목 | Highly-sensitive H2 sensor operating at room temperature using Pt/TiO2 nanoscale Schottky contacts |
| 초록 | Despite growing demands for high performance hydrogen (H2) sensors operating at low temperature, metal oxides-based H2 sensors intrinsically require an elevated operating temperature due to a high activation energy for gas adsorption on metal oxides surface. In order to lower operating temperature, catalytic noble metals have been utilized as a Schottky contact on a metal oxides layer. In such a Schottky device, large current modulation becomes possible because H2 molecules are dissociated into H atoms and they diffuse into the junction lowering of the Schottky barrier by dipole layer formation even at low temperature. However, previously reported H2 sensors based on the Schottky contacts showed no or small responses at room temperature due to limited gas diffusion and current modulation caused by their device architecture. In this work, we demonstrate a highly-sensitive H2 sensor operating at low temperatures, even at room temperature, enabled by Pt/TiO2 nanoscale Schottky contacts which can fabricated by conventional microfabrication techniques. The Schottky device shows very promising low-temperature performance including high H2 response (Rair/RH2 ＞ 780 at 75 ℃, and ＞ 100 at room temperature), and short response/recovery times (55/4 seconds at 75 ℃) in air ambient. Such a high performance is attributed to our unique device architecture having highly exposed nanoscale Schottky contact to the ambient and the top-and-bottom electrodes configuration, which takes full advantages offered by the Schottky devices. Also, we investigated temperature- and ambient-dependence in H2 sensing behaviors to propose sensing mechanism in our device. We believe our approach can be a good solution to realize high performance H2 sensor operating at room temperature. |
| 저자 | 권현아, 이유나, 황선용, 김종규 |
| 소속 | 포항공과대 |
| 키워드 | Hydrogen sensor; nanoscale Schottky contact; room temperature |
