| 학회 | 한국재료학회 |
| 학술대회 | 2011년 봄 (05/26 ~ 05/27, 제주 휘닉스 아일랜드) |
| 권호 | 17권 1호 |
| 발표분야 | A. Information and Sensor Materials(정보소재 및 센서) |
| 제목 | Highly sensitive gas sensors based on nanostructured TiO2 thin films |
| 초록 | TiO2 is a promising material for gas sensors. To achieve high sensitivities, the material should exhibit a large surface-to-volume ratio and possess the high accessibility of the gas molecules to the surface. Accordingly, a wide variety of porous TiO2 nanomaterials synthesized by wet-chemical methods have been reported for gas sensor applications. Nonetheless, achieving the large-area uniformity and comparability with well-established semiconductor production processes of the methods is still challenging. An alternative method is soft-templating which utilizes nanostructured inorganic or organic materials as sacrificial templates for the preparation of porous materials. Fabrication of macroporous TiO2 films and hollow TiO2 tubes by soft–templating and their gas sensing applications have been reported recently. In these porous materials composed of assemblies of individual micro/nanostructures, the form of links or necks between individual micro/nanostructures is a critical factor to determine gas sensing properties of the material. However, a systematic study to clarify the role of links between individual micro/nanostructures in gas sensing properties of a porous metal oxide matrix is thoroughly lacking. In this work, we have demonstrated a fabrication method to prepare highly-ordered, embossed TiO2 films composed of anatase TiO2 hollow hemispheres via soft-templating using polystyrene beads. The form of links between hollow hemispheres could be controlled by O2 plasma etching on the bead templates. This approach reveals the strong correlation of gas sensitivity with the form of the links. Our experimental results highlight that not only the surface-to-volume ratio of an ensemble material composed of individual micro/nanostructures but also the links between individual micro/nanostructures play a critical role in evaluating the sensing properties of the material. In addition to this general finding, the facileness, large-scale productivity, and compatability with semiconductor production process of the proposed fabrication method promise applications of the embossed TiO2 films to high-quality sensors. |
| 저자 | 장호원, 문희규, 김도홍, 심영석, 윤석진 |
| 소속 | 한국과학기술(연) |
| 키워드 | Gas sensors; TiO2; nanostructured; embossed; nanotubular |
