| 1. |
- Mathijssen, Simon G. J., et al.
(författare)
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Manipulating the local light emission in organic light-emitting diodes by using patterned self-assembled monolayers
- 2008
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Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095. ; 20:14, s. 2703-
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Tidskriftsartikel (refereegranskat)abstract
- Patterned organic light-emitting diodes are fabricated by using microcontactDrinted self-assembled monolayers on a gold anode (see background figure). Molecules with dipole moments in opposite directions result in an increase or a decrease of the local work function (foreground picture), providing a direct handle on charge injection and enabling local modification of the light emission
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| 2. |
- Smits, Edsger C. P., et al.
(författare)
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Bottom-up organic integrated circuits
- 2008
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 455:7215, s. 956-959
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Tidskriftsartikel (refereegranskat)abstract
- Self- assembly - the autonomous organization of components into patterns and structures(1) - is a promising technology for the mass production of organic electronics. Making integrated circuits using a bottom- up approach involving self- assembling molecules was proposed(2) in the 1970s. The basic building block of such an integrated circuit is the self- assembled- monolayer field- effect transistor ( SAMFET), where the semiconductor is a monolayer spontaneously formed on the gate dielectric. In the SAMFETs fabricated so far, current modulation has only been observed in submicrometre channels(3-5), the lack of efficient charge transport in longer channels being due to defects and the limited intermolecular pi-pi coupling between the molecules in the self-assembled monolayers. Low field- effect carrier mobility, low yield and poor reproducibility have prohibited the realization of bottom- up integrated circuits. Here we demonstrate SAMFETs with long- range intermolecular pi - pi coupling in the monolayer. We achieve dense packing by using liquid- crystalline molecules consisting of a pi- conjugated mesogenic core separated by a long aliphatic chain from a monofunctionalized anchor group. The resulting SAMFETs exhibit a bulk- like carrier mobility, large current modulation and high reproducibility. As a first step towards functional circuits, we combine the SAMFETs into logic gates as inverters; the small parameter spread then allows us to combine the inverters into ring oscillators. We demonstrate real logic functionality by constructing a 15- bit code generator in which hundreds of SAMFETs are addressed simultaneously. Bridging the gap between discrete monolayer transistors and functional self-assembled integrated circuits puts bottom- up electronics in a new perspective.
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| 3. |
- de Boer, J., et al.
(författare)
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United Nations Environment Programme Capacity Building Pilot Project : training and interlaboratory study on persistent organic pollutant analysis under the Stockholm Convention
- 2008
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 617:1-2, s. 208-215
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Tidskriftsartikel (refereegranskat)abstract
- Within the framework of a United Nations Environment Programme (UNEP) Capacity Building Project for training of laboratory staff in developing countries on persistent organic pollutant (POP) analysis, an interlaboratory study was organised following an initial evaluation of the performance of laboratories (reality check) and a series of training sessions. The target compounds were polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP). Seven laboratories from five countries (Ecuador, Uruguay, Kenya, Moldova, and Fiji) participated. Most of the laboratories had no experience in determining PCBs. Although chromatograms improved considerably after the training and installation of new gas chromatographic (GC) columns at participating laboratories, the level of performance in the interlaboratory study was essentially on par with the moderate performance level achieved by European POP laboratories in the 1980s. Only some individual results were within +/-20% of the target values. The relative standard deviations (R.S.D.s) in POP concentrations determined by laboratories in a sediment sample were >200% in a number of cases. The results for a certified herring sample were better with at least some R.S.D. values below 50% and most below 100%. Clean up was as one of the main sources of error. After inspection it was ascertained that training of laboratory staff and investments in simple consumables such as glassware and GC columns would help to improve the quality of the analysis more than major investments in expensive instrumentation. Creating an effective network of POP laboratories at different continents together with a series of interlaboratory studies and workshops is suggested to improve the measurements of POPs in these countries.
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