Δευτέρα 31 Οκτωβρίου 2016
- Εμμανουήλ Σπανάκης
- Τμήμα Επιστήμης και Τεχνολογίας Υλικών, Πανεπιστήμιο Κρήτης
- Tungsten/vanadium oxides for cold-electron emission and thermally controlled VIS/IR transmission
- Αίθουσα A2 (Α115-Α117) του κτιρίου Επιστήμης Υπολογιστών
Metal oxide semiconductors have attracted a lot of research interest over the last decades in an effort either to improve their properties in existing applications or to render them realizable in novel ones. Applicable fields include, but are not limited to, optoelectronics, renewable energy, food and clothing, cosmetics and medicine. The first part of my presentation will show the results of our effort to hydrothermally grow spiky nanostructures of tungsten trioxide for use as cold electron emitters. The growth technique is known to be very simple but also very time consuming thus we focused on finding the proper conditions to produce good quality material at reasonable amounts of time. The second and biggest part of my presentation will be devoted to the deposition and study of vanadium dioxide. The material is thermochromic i.e. at a certain temperature/range both its infrared transmittance/reflectance and its electrical resistivity change, the former by many decades and the latter by several orders of magnitude! We used the atmospheric pressure chemical vapor deposition method and focused our research in finding proper precursor gas flow conditions and favorable substrates for fabrication of nanostructured VO2 having as steep thermochromic changes and as narrow hysteresis loops as possible.