Search results for "Organic electronic"

Modulating the Electrical Properties of Organic Heterojunction Devices Based On Phthalocyanines for Ambipolar Sensors.

2020

International audience; HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Polymeric Thin Films for Organic Electronics: Properties and Adaptive Structures

2013

This review deals with the correlation between morphology, structure and performance of organic electronic devices including thin film transistors and solar cells. In particular, we report on solution processed devices going into the role of the 3D supramolecular organization in determining their electronic properties. A selection of case studies from recent literature are reviewed, relying on solution methods for organic thin-film deposition which allow fine control of the supramolecular aggregation of polymers confined at surfaces in nanoscopic layers. A special focus is given to issues exploiting morphological structures stemming from the intrinsic polymeric dynamic adaptation under non-…

Thin Film Organic Thermoelectric Generator Based on Tetrathiotetracene

2017

This is the peer reviewed version of the following article: K. Pudzs, A. Vembris, M. Rutkis, S. Woodward, Adv. Electron. Mater. 2017, 1600429, which has been published in final form at http://onlinelibrary.wi...002/aelm.201600429/full This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

Controlling the mode of operation of organic transistors through side chain engineering

2016

Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode…

Conformationally rigid molecular and polymeric naphthalene-diimides containing C6H6N2 constitutional isomers

2021

Organic thin films based on naphthalenediimides (NDIs) bearing alkyl substituents have shown interesting properties for application in OLEDs, thermoelectrics, solar cells, sensors and organic electronics. However, the polymorphic versatility attributed to the flexibility of alkyl chains remains a challenging issue, with detrimental implications on the performances. Aryl analogues containing C6H6N2 constitutional isomers are herein investigated as one of the possible way-out strategies. The synthesis of molecular and polymeric species is described, starting from naphthaleneteracarboxyldianhydride with isomeric aromatic amines and hydrazine. The materials are fully characterized by spectrosco…

O-Doped Nanographenes: A Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed-Valence Complexes

2020

Herein we report an efficient synthesis to prepare O‐doped nanographenes, which derive from the longitudinally and latitudinally p‐extension of pyrene. The derivatives are highly fluorescent and feature low‐oxidation potentials. Exploiting electrooxidation, crystals of cationic mixed valence (MV) complexes were grown in which the organic salts organize into face‐to‐face p‐ p stacks, a favorable solid‐state arrangement for organic electronics. Variable‐temperature EPR measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar p‐stacking architectures. Electric measurements of single crystals of the MV salts exhibited a semiconduct…

Fabrication of MIM and MIS Structures for Organic Electronics

2008

A simple method for measuring OLEDs efficiency

2015

External quantum efficiency (EQE) of organic light emitting diodes (OLEDs) is among the most important parameters for devices assessment and for comparing OLEDs performance. The EQE is the ratio of the total number of photons emitted by the OLED in all directions to the number of electrons injected.

DC lifetime of encapsulated organic light emitting diodes

2016

Organic light emitting diodes (OLEDs) are ideal sources for chemical and biological optical sensors, due to their simplicity, low cost (disposable applications) and possibility to be integrated on chip and fabricated in the form of large 2D arrays (microarray fluorescence) even on flexible plastic substrates. OLEDs with lifetimes of a few hundreds of hours at initial luminance values in the range (500÷1000) cd/m 2 are suitable for the above applications, but these lifetimes can be achieved only by a proper encapsulation. Fast, simple and inexpensive encapsulation methods are highly desirable to keep the low cost profile and for this reasonwe report two different encapsulation structures and…

Rational computing of energy levels for organic electronics: the case of 2-benzylidene-1,3-indandiones

2016

Device engineering in organic electronics, an active area of research, requires knowledge of the energy levels of organic materials (traditionally but ambiguously denoted as HOMO and LUMO). These can be effectively determined by electrochemical investigation, but yet more effective would be quantum chemical (QC) computation of these quantities. However, there is no consensus on the computational method in the research community. Ongoing discussions often focus on choosing the right density functional method, but neglect other model parameters, in particular, the basis set. This study considers comparison of various methodologies and parameters for predicting ionization energy I and electron…