Devices for Large Area Electronics
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This activity is mainly focused on devices for large area electronic applications, such as flat panel displays, sensors and smart user interfaces. A strong effort is concentrated on the development of low temperature processes to fabricate devices on polymeric substrates for flexible display and electronic applications. In particular, the group has developed know-hows on polycrystalline silicon thin film transistors (TFTs), made by excimer laser crystallization technique, organic TFTs, using an innovative technology of buffer layers for devices based on pentacene. More recently, the group has started new activities in the field of nanostructured materials (Si nanowires), for both sensor and photovoltaic applications, and oxide semiconductors, for TFT applications. |
Group Leader: Guglielmo Fortunato |
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The group has a long standing expertise in the field of devices for large area electronic applications, such as thin film transistors (TFTs) for active matrix for flat panel displays, sensors, organic electronics and smart user interfaces. Research activities include device design and fabrication, electrical characterization, device analysis performed by 2D and 3D numerical simulations, circuit design and simulations. The possibility to cover the entire range of activities around the technology and physics of devices is related to the microfabrication facility present at IMM-CNR in Rome. The research activity has been supported over the last years by a number of European (FlexiDis, FLASH, ECAM III) and National (Plast_Ics, Micropolis-FIRB) Projects and by closely interacting with industries through research contracts, including ST-Microelectronics, Philips and THALES. The activity has been focused on specific aspects regarding the development of low temperature process for the fabrication of TFTs on plastic substrates and on the study of the electrical properties, including reliability issues (hot-carrier induced device degradation and self-heating related instabilities), high electric field induced phenomena and drain field engineering. Two TFT technologies have been recently developed on polyimide substrates, based on organic (pentacene) and inorganic materials (polycrystalline silicon). More recently, the activity has been organized into three main areas:
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 Download the activity brochure |
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Group Leader: |
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| Guglielmo Fortunato | ||||||||||||
Research Staff: |
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Partners: |
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| LETI Grenoble, France | ||||||||||||
| University of Stuttgart, Germany | ||||||||||||
| Ecole Polytechnique Paris, France | ||||||||||||
| CNRS Paris, France | ||||||||||||
| Lambda Physics, Germany | ||||||||||||
| Dipartimento di Fisica Universita' di Catania, Italy | ||||||||||||
| University of Utrecht, Holland | ||||||||||||
| ENI Novara, Italy | ||||||||||||
Projects related to activity |
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| Plast_ICS, funded by the Italian Ministry of Research and Coordinated by ST-Microelectronics | ||||||||||||
| FlexiDis | ||||||||||||
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FLASH Project: "Fundamentals and Applications of Laser Process for Highly Innovative MOS Technology", European Union Fifth Framework Program |
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MICROPOLIS Project (Microsistemi a base di polimeri)– funded in the FIRB Program – "Nanotecnologie, microtecnologie, sviluppo integrato dei materiali" |
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| ECAM III | ||||||||||||
Nanowires (NWs) are going to become the building blocks of several kinds of future devices [1-3], and for this reason they are presently among the most pursued topics in solid-state physics. This newly started activity on the growth of silicon nanowires has the objective to develop growth protocols compatible with low-temperature device processes and able to produce NWs with excellent electronic properties. NWs are generally grown after the vapour-liquid-solid model [4], by using a metal nanoparticle (NP), the catalyst, that induces and dictates the growth. The NP is then found at the free end of the NW. The most commonly used metal is gold. However, the catalyst may diffuse into the wires inducing unwished changes of the NW electronic properties. In particular, Au should be avoided when growing Si NWs or integrating III-V NWs with Si substrates, being Au a very efficient carrier trap in Si. Growths at low temperatures with catalysts alternative to gold or without the use of any external catalyst has then been the first practical goal to achieve. High density NWs obtained on a n-Si(111) surface etched with a 40% NH4F solution is shown in Figure 1. Si(110) cleavage surfaces and microcrystalline Si obtained by laser annealing of amorphous Si also induce the growth of Si NWs. (For details see: http://iopscience.iop.org/0957-4484/21/25/255601). Other ongoing researches concern the use of In as growth catalyst. A typical In-catalyzed Si NWs grown in our laboratory can be seen in Fig. 2. They are very narrow and clearly show an In nanoparticle on their top. Other activities include optical reflectivity from Si NWs and the fabrication of nanowires-based chemical sensors. Through a collaboration with the University of Tor Vergata (Roma) the nanowires are being tested as field emitters and in hybrid photovoltaic cells.
Nanostructured materials, such as Si nanowires, for both sensor and photovoltaic applications.
Fig. 1. (a) Low-magnification SEM image of Si NWs grown of an etched n-Si(111) surface. The sample is inclined by 60°. Notice the abruptness of the border between regions with and without wires. (b) Detail of (a): the homogeneous morphology of the wires in all their length is apparent.
Figure 2. An In-catalysed Si nanowire
[1] Yat Li, Fang Qian, Jie Xiang, and Charles M. Lieber, Materials Today 9, 18, 2006.
[2] C. Thelander, P. Agarwal, S. Brongersma, J. Eymery L. F. Feiner, A. Forchel, M. Scheffler, W. Riess, B. J. Ohlsson,U. Gösele, and L. Samuelson, Materials Today 9, 28, 2006.
[3] Peter J. Pauzauskie and Peidong Yang Materials, Today 9, 36, 2006.
[4] R. S. Wagner and W. C. Ellis, Appl. Phys. Lett. 4, 89, 1964
Research Staff:
Faustino Martelli
Annalisa Convertino
Massimo Cuscuna'
Guglielmo Fortunato
Luigi Mariucci
