Interface Dipole : Effects on Threshold Voltage and Mobility for both Amorphous and Poly-crystalline Organic Field Effect Transistors

We report a detailed comparison on the role of a self-assembled monolayer (SAM) of dipolar molecules on the threshold voltage and charge carrier mobility of organic field-effect transistor (OFET) made of both amorphous and polycrystalline organic semiconductors. We show that the same relationship between the threshold voltage and the dipole-induced charges in the SAM holds when both types of devices are fabricated on strictly identical base substrates. Charge carrier mobilities, almost constant for amorphous OFET, are not affected by the dipole in the SAMs, while for polycrystalline OFET (pentacene) the large variation of charge carrier mobilities is related to change in the organic film structure (mostly grain size).Comment: Full paper and supporting informatio

Negative Differential Resistance, Memory and Reconfigurable Logic Functions based on Monolayer Devices derived from Gold Nanoparticles Functionalized with Electro-polymerizable Thiophene-EDOT Units

We report on hybrid memristive devices made of a network of gold nanoparticles (10 nm diameter) functionalized by tailored 3,4(ethylenedioxy)thiophene (TEDOT) molecules, deposited between two planar electrodes with nanometer and micrometer gaps (100 nm to 10 um apart), and electropolymerized in situ to form a monolayer film of conjugated polymer with embedded gold nanoparticles (AuNPs). Electrical properties of these films exhibit two interesting behaviors: (i) a NDR (negative differential resistance) behavior with a peak/valley ratio up to 17, and (ii) a memory behavior with an ON/OFF current ratio of about 1E3 to 1E4. A careful study of the switching dynamics and programming voltage window is conducted demonstrating a non-volatile memory. The data retention of the ON and OFF states is stable (tested up to 24h), well controlled by the voltage and preserved when repeating the switching cycles (800 in this study). We demonstrate reconfigurable Boolean functions in multiterminal connected NP molecule devices.Comment: Full manuscript, figures and supporting information, J. Phys. Chem. C, on line, asap (2017

Metal/organic/metal bistable memory devices

We report a bistable organic memory made of a single organic layer embedded between two electrodes, we compare to the organic/metal nanoparticle/organic tri-layers device [L.P. Ma, J. Liu, and Y. Yang, Appl. Phys. Lett. 80, 2997 (2002)]. We demonstrate that the two devices exhibit similar temperature-dependent behaviors, a thermally-activated behavior in their low conductive state (off-state) and a slightly "metallic" behavior in their high conductive state (on-state). This feature emphasizes a similar origin for the memory effect. Owing to their similar behavior, the one layer memory is advantageous in terms of fabrication cost and simplicity

Negative differential resistance and non-volatile memory in hybrid redox organic/nanoparticle devices

International audienc

UTILIZATION OF SECONDARY CON- STRUCTION MATERIALS IN A LANDFILL

SUMMARY: Many landfills in Sweden as well as in Europe are subject to closure in the near future. Roughly 2,000 hectares of landfill area in Sweden have to be covered, equivalent to almost one hundred million tonnes of construction material. In addition to material costs in the order of tens of billions Euro, this also puts a strain on the environment through the exploitation of virgin materials. The deadline for this adoption to the EU Landfill directive is due in 2008 but it is already apparent that many landfills will not meet the deadline. Many landfill operators are considering alternative cover designs in order to reduce resource spending. However, there is a fair amount of uncertainty with regard to functional and environmental consequences of using alternative materials, both from the side of the companies and the authorities. It is necessary to characterise these materials in terms of chemical and physical properties. For example, the leaching of the materials is of great interest in order to estimate the requirements and design of future leachate treatment. 1

Interprétation des caractéristiques “courant-tension" dans les structures métal/polymère conducteur/métal

Le travail présenté concerne l'interprétation des caractéristiques courant-tension dans les diodes électroluminescentes à couche active polymères conducteurs réalisées à partir du poly(N-butylcarbazole) (PBuC) et du poly(N-octylthiophène) (P3OT). La caractérisation électrique de ces diodes est effectuée en fonction de différents paramètres (épaisseur et température) pour le PBuC et en régime dynamique pour le P3OT. A température ambiante et au dessus, le courant dans les structures PBuC s'interprète par le modèle d'émission-diffusion Richardson-Schottky au dessus de la barrière ITO/PBuC . A basse température, les résultats correspondent à une émission de type tunnel. Avec les structures P3OT, le courant est limité par l'interface POT/Al qui se comporte comme un contact Schottky

Optimization of pentacene double floating gate memories based on charge injection regulated by SAM functionalization

International audiencePentacene based double nano-floating gate memories (NFGM) by using gold nanoparticles (Au NPs) and reduced graphene oxide (rGO) sheets as charge trapping layers are prepared and demonstrated. Particularly, the NFGM chemically treated by 2,3,4,5,6-pentafluorobenzenethiol (PFBT) self-assembled monolayers (SAM) exhibits excellent memory performances, including high mobility of 0.23 cm2V-1s-1, the large memory window of 51 V, and the stable retention property more than 108 s. Comparing the performances of NFGM without treating with PFBT SAM, the improving performances of the memory devices by SAM modification are explained by the increase of charge injection, which could be further investigated by XPS and UPS. In particular, the results highlight the utility of SAM modulations and controlling of charge transport in the development of organic transistor memories