Mednarodni projekti
Development of novel conjugated molecular nanostructures by lithography and their transport scaling aspects
Organizacije (1)
| št. |
Evidenčna št. |
Razisk. organizacija |
Kraj |
Matična številka |
Štev. publikacijŠtev. publikacij |
| 1. |
1540 |
Univerza v Novi Gorici |
Nova Gorica |
5920884000 |
14.060 |
Povzetek
New nanostructures of conjugated molecules exhibiting enhanced charge mobility are pursued by template growth of the active material onto nanopatterned field effect transistors (FET). Downscaling the electrode spacing in interdigitated FETs from micrometers will results into: i) reduction of defects and grain boundaries in the active region, ii) higher molecular order as a consequence of the fact that ultra-thin films of the active molecule can be used; iii) control of order and anisotropy through the template features. Our experiments will bridge the gap between micro- and nanometer-scale transport, reveal the possible crossover between different transport regimes in conjugated materials, and assess the limit for the intrinsic material response. These are crucial for improving a wide class of materials relevant to plastic electronics. Moreover, correlation between transport and morphology, and optical properties on the nanoscale will be established. The device fabrication will be carried out by integration of unconventional parallel lithography techniques and growth, and will be upscaled in view of industrial production of low-cost large number organic integrated circuits.The deliverables have largely been met.The project has demonstrated:- the ability to integrate nanofabrication techniques, bottom up and top down, with molecular thin film growth and other bottom up organisation phenomena;-the capability of turning a variety of nanofabrication approaches into suitable techniques for organic materials and devices;-the possibility to enhance the transport response of well-organised organic semiconductors by downscaling;-the re-definition of the design rules of devices in order to promote self-organisation of organic active materials in the device;-the observation of different regimes of FET response upon downscaling;-the enhancement of charge mobility in FET a) by controlling the organization and architecture of the transport layer; b) by downscaling the transport layer; c) by chemical and physical control of the relevant interfaces.-the reproducibility of experiments and property measurements on devices and nanostructures at different partner's sites, and procedures to flow samples around for experiments, as an example of prototypical standardisation;-the demonstration of upscaled fabrication of working FET test patterns with an unconventional approach. MONA LISA has demonstrated an excellent level of cooperative research at EU level. There has been a substantial cross-fertilisation among the different laboratories. Two joint patents between CNR and CSIC have been filed during the course of MONA LISA (one has already been extended internationally), as a result of their collaborative research. These have been the first two joint patents for these institutions, and prelude to a joint valorisation of IPR. With the addition of NAS partners, the deliverables have been enriched with materials (1 g of pure organic semiconductors and different molecules for assembly on Au electrodes), and complemtary techniques for understanding transport and optical properties. New scanning electrical probes able to map a working organic FET have been demonstrated. Also, X-ray diffraction experiments were performed in May 2003 and May 2004 at ESRF on MONA LISA relevant samples. Both these activities were not originally foreseen. Major drawbacks with respect to the expectated results were:-the problem of contact resistance remains relevant upon downscaling FETs to submicrometer channel lengths;-the investigation of the scaling behaviour of optical properties by SNOM has been redirected since SNOM was judged to be not a dependable technique. The implementation of Laser Scanning Confocal Microscopy during the course of the project took time, and although the technique lead to new and interesting observations, a systematic work on nanopatterned structures (D13) was not carried out. As a back up, anisotropy was studied by Raman confocal microscopy and by
