Prof Thomas Lippert
Materials Group, Paul Scherrer Institut, Villigen PSI, Switzerland
Date: Wednesday 20 February 2008
Time: 2.00pm
Venue: Lecture Theatre C, Building 46, room 2005
While pulsed laser deposition (PLD) is a suitable technique for the deposition of inorganic materials other techniques are needed for organic, polymeric, and biological materials and for processes where a lateral resolution is required. One of these methods is laser-induced forward transfer (LIFT) which allows the precise transfer of material patterns onto a substrate. The material layer is removed by laser ablation from a donor substrate and deposited onto a receiver substrate that is facing the donor substrate. This method is suitable for metals, but not for sensitive organic/biologic materials, that degrade easily upon irradiation with UV photons or by a thermal load. To overcome this limitation, we developed a variation of the LIFT technique using a sacrificial layer of a photosensitive polymer. This photosensitive polymer has been designed for irradiation at 308 nm and decomposes completely into gaseous products that propel the transfer layer mechanically onto the receiver. The transfer process has been analyzed in detail by shadowgraphy, which shows that in the case of a gap between donor and receiver the shock wave reflected by the receiver may destroy the material flyer. We could show that LIFT with a sacrificial layer allows the transfer of very sensitive materials, e.g. functional pixels of electro-active polymer for building organic light-emitting diode (OLED) displays.
Thomas Lippert studied Chemistry at the University of Bayreuth. After the PhD he worked for Wacker Chemistry. Then he went as a Science and Technology Agency (STA) of Japan / Alexander v. Humboldt (AvH) Postdoctoral Fellow to the National Institute of Materials and Chemical Research (NIMC) in Tsukuba, Japan. After Japan he went to Los Alamos National Laboratory, USA, where he also became a Technical Staff Member. In 1999 Thomas Lippert went as Senior Scientist to the Paul Scherrer Institut, Switzerland. He is heading the Materials group there. In 2002 Thomas received his Habilitation at ETH Zurich in Physical Chemistry and became private lecturer (Privatdozent). His main research areas are thin film deposition, mainly for renewable energy applications, by pulsed laser deposition or laser-induced forward transfer. Other main topics are materials development and various analytical techniques for these processes. Thomas Lippert has served as co-chair of 4 international conferences, has or is supervising 14 PhD students, and has published ~ 170 papers including several book chapters. He is also member of the executive committee of the E-MRS and was or is committee member of > 12 international conferences.