Organic semiconductors are very promising candidates as starting materials for the manufacture of cheap, large area and flexible electronic components such as transistors, diodes and sensors on a scale ranging from micro to nano. A condition for success in achieving this goal is the ability to join components together with electrically conducting links in other words, to create an electronic circuit. Empa scientists have developed a new method which allows them to create simple networks of organic nanowires.
The origin: an EU project called PHODYE
When Spanish physicist Angel Barranco returned to Valencia after a three year research stint at Empa, he initiated the EU project PHODYE with, among others, his old Empa colleagues. The aim is to develop highly sensitive gas sensors, for monitoring road vehicle emissions, for example, or for providing laboratory staff and mine workers with an early warning of the presence of poisonous substances. The sensors are based on fluorescing thin films which change color and fluoresce on contact with certain gas molecules.
"We were thinking in terms of a sort of electronic key for security applications, which would only react to certain optical conditions," explains Empa physicist Pierangelo Groening. Necessary for this are transparent, strongly fluorescing thin films, so Groening and Barranco developed a plasma-deposition process in order to store fluorescing dye molecules such as metallo-proyphins, perylenes and phthalocyanines unmodified and at high concentrations in SiO2 or TiO2 layers.
It soon became apparent that if certain gas molecules deposited on dye particles in the thin films, then these fluoresced at different wavelengths and the thin film c
|Contact: Sabine Voser|
Swiss Federal Laboratories for Materials Testing and Research (EMPA)