Transparent Oxide-Electronics
Transparent oxide electronics is a novel area of research that focuses on the investigation of transparent electronic devices and circuits. This technology involves the class of materials called metal oxides which exhibit a large band gap.
The transparent property of these materials enables a large field of new applications in the display area starting from the automotive sector (e.g. warning hints in the windshield) to medical and safety engineering (head-up displays, augmented reality).
Alphanumeric transparent display
A key component of today's active-matrix displays is the thin-film transistor (TFT). This device is required for the driver electronics of the display. To achieve a fully transparent display the TFT must also consist of transparent materials. This requirement cannot be fulfilled by the well established a-Si technology. Therefore, the oxide electronics marks an important new key technology.
(left) typical TFT driver circuit for pixel switching (right) TFT structure
Subject of current research at the institute of Electronic Devices are basic research questions regarding the process technology of thin film transistors. Furthermore, the appropriate encapsulation of TFTs in terms of their application plays an important role. In addition, we are concerned with the development of innovative device concepts that will enhance the integration of metal oxide.
Transparent TFTs visible at increased reflection
Other important areas of our activities are reliability and stability studies of oxide TFTs. A high reliability is an essential requirement for a trustworthy performance in critical applications like within the safety section. Hereby, the deep impact of environmental factors on the TFT operation is mainly investigated.
Publications:
- M. Fakhri, H. Johann, P. Görrn, and T. Riedl:Water-related instability in zinc tin oxid thin-film transistors (Talk)TCM, Crete, 10B-239 (2012).
- M. Fakhri, H. Johann, P. Görrn, and T. Riedl:Water as origin of hysteresis in zinc tin oxide thin-film transistorsACS Appl. Mater. & Interfaces 4, 4453 (2012).
- M. Fakhri, H. Johann, P. Görrn, T. Riedl: Origin of hysteresis in zinc-tin-oxide thin-film transistors (Talk) ITC, Lisbon, S3 (2012).
- M. Fakhri, P. Görrn, A. Raeupke, T. Weimann, P. Hinze, T. Riedl: Enhanced Stability of Oxide Thin Film Transistors Deposited at High Temperatures (Talk) MRS Fall Meeting, Boston, M7.8 (2011).
- M. Fakhri, P. Görrn, T. Weimann, P. Hinze, and T. Riedl:Enhanced stability against bias-stress of metal-oxide thin film transistors deposited at elevated temperaturesAppl. Phys. Lett. 99, 123503 (2011).
- T. Riedl, P. Görrn, and W. Kowalsky:Transparent Electronics for See-Through AMOLED DisplaysIEEE/OSA J. Displ. Technol. 5, 810 (2009).
- P. Görrn, F. Ghaffari, T. Riedl, and W. Kowalsky:Zinc Tin Oxide Based Driver for Highly Transparent Active Matrix OLED DisplaysSolid State Electron. 53, 329 (2009).
- P. Görrn, P. Hölzer, T. Riedl, W. Kowalsky, J. Wang, T. Weimann, P. Hinze, and S. Kipp:Stability of transparent zinc tin oxide transistors under bias stressAppl. Phys. Lett. 90, 063502 (2007).
- Patrick Görrn, Michelle Sander, Jens Meyer, Michael Kröger, Eike Becker, Hans-Hermann Johannes, Wolfgang Kowalsky, and Thomas Riedl:Towards See-Through Displays: Fully Transparent Thin-Film Transistors Driving Transparent Organic Light Emitting DiodesAdv. Mater. 18, 738 (2006).
