Session 32: Optoelectronics, Displays, and Imagers Thin Film Transistors for Imaging and Displays

Wednesday, December 7, 9:00 a.m.
Imperial Ballroom B
Co-Chairs: Soeren Steudel, IMEC
Ioannis (John) Kymissis

9:05 AM
32.1 An Active Artificial Iris Controlled by a 25-µW Flexible Thin-Film Driver, F. De Roose, S. Steudel, K. Myny, M. Willegems, S. Smout, M. Ameys, P. Malinowski, R. Gehlhaar, R. Poduval, X. Chen, J. De Smet, A. Vásquez Quintero*, H. De Smet*, W. Dehaene** and J. Genoe, imec, *UGent, **KULeuven

We show an active artificial iris with solely thin-film components, wherein several LCD elements are powered using thin-film photovoltaics (TFPV) and a-IGZO oxide TFT electronic power drive. Key aspects for the drive are size and low power consumption. We show power consumption down to 25µW for the full iris.

9:30 AM
32.2 High-Performance and Reliable Elevated-Metal Metal-Oxide Thin-Film Transistor for High-Resolution Displays, L. Lu, J. Li, H. S. Kwok and M. Wong, the Hong Kong University of Science and Technology

Incorporated with the annealing-induced source/drain (S/D), elevated-metal metal-oxide (EMMO) thin-film transistor (TFT) was proposed to provide an etch-stop (ES) layer while retain a small device size for high- resolution displays, which could not be combined in conventional TFT architectures. The “defect- populated” S/D and “defect-free” channel enabled the high performance metrics: a competitive field-effect mobility of ~14 cm2/Vs; an extremely low off-current of ~10-18 A; an impressive on/off ratio of ~1012; and the superior reliability against temperature, bias and current stresses.

9:55 AM
32.3 Polycrystalline Silicon TFTs on a Paper Substrate Using Solution-Processed Silicon, M. Trifunovic, P. Sberna, T. Shimoda* and R. Ishihara, Delft University of Technology, *Japan Advanced Institute of ScienceTechnology

Polycrystalline silicon TFTs have been fabricated for the first time directly on a paper substrate using a liquid silicon solution. The fabrication temperature was limited to 100C. This work serves as a proof of concept, and opens the pathway toward low-cost, flexible electronics combined with the high performance of silicon.

10:20 AM
32.4 High-detectivity Printed Organic Photodiodes for Large Area Flexible Imagers (Invited), A. Pierre and A. Arias, University of California, Berkeley

10:45 AM
32.5 Dual-Gate Photosensitive FIN-TFT with High Photoconductive Gain and Near-UV to Near-IR Responsivity, H. Ou, K. Wang, J. Chen, A. Nathan*, S. Z. Deng and N. Xu, Sun Yat-sen Univeristy, *University of Cambridge

We report the first three-dimensional dual-gate photosensitive a-Si:H thin-film transistor operating in the sub-threshold regime for low-level light detection. The measured photoconductive gain is greater than 100 with photo-response ranging from near- ultraviolet to near-infrared wavelengths, making it a potential candidate as an image sensor for UV, visible, IR and X-rays.

11:10 AM
32.6 Extending the Functionality of FDSOI N- and P-FETs to Light Sensing, L. Kadura, L. Grenouillet, T. Bedecarrats, O. Rozeau, N. Rambal, P. Scheiblin, C. Tabone, D. Blachier, O. Faynot, A. Chelnokov and M. Vinet, CEA LETI

We demonstrate that FDSOI transistors co- integrated with a diode implemented below the buried oxide (BOX) become strongly sensitive to visible light. The carriers photogenerated in the diode create a Light-Induced VT Shift (LIVS) in both NFET & PFET transistors by means of capacitive coupling, without direct electrical connection between the photodiode and the sensing transistor. This optical back biasing effect is carefully examined as a function of both transistor and diode technological parameters. The experimental results are supported by TCAD simulations, suggesting that the proposed FDSOI/photodiode co-integration scheme can be used for efficient photodetectors. We also study the transient effects, and propose an efficient reset mechanism. Finally, we demonstrate for the first time that SRAM cells can be made controllable by light illumination.