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Conductive polymers are a very promising alternative for the fabrication of transparent conductive materials. They have many advantages compared to existing materials, like a low-cost and a high flexibility. However, electrical conductivity still needs to be improved. We report a straightforward solution-based approach for the fabrication of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films with conductivity as high as 6046 ± 510 S cm−1, based on accurate water content control during the polymerization step. The crystallinity improvement is evidenced by GIWAXS characterization, and low temperature electrical conductivity measurements give new insights on the transport mechanisms at stake. This very high conductivity is, to our knowledge, the highest reported value for solution-based synthesis of PEDOT based materials. [ABSTRACT FROM AUTHOR]

In this work, the authors study active layers of organic photodetector devices containing phenyl-C61- butyric acid methyl ester and Poly[(4,8-bis-(2-ethylhexyloxy)-benzo(1,2-b:4,5-b')dithiophene)-2,6- diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-C). Thin films are examined by x-ray photoemission spectroscopy coupled with argon gas cluster ion sputtering. The use of massive cluster projectiles instead of monoatomic ions has the advantage of not destroying the chemical structure of organic materials under study. The authors show how simulated aging influences the chemistry of these blends and how these alterations extend from sample surface into the bulk of the film. The authors identify several possible processes resulting from aging, including C=O bond breakage and PBDTTT-C diffusion. [ABSTRACT FROM AUTHOR]

Optimization of light emitting devices when light is trapped within the dielectric structures opens the question of the management of light propagation and of control of the directionality of extracted light. These phenomena are closely connected to the so‐called extraction length of light propagating within the device, a parameter that is poorly discussed when considering the design and architecture of devices. In this work, a straightforward method for the measurement of the extraction length in the case of luminescent sol–gel films patterned with a 2D photonic bandgap structure is presented. Quantitative information usually obtained by spectro‐angular measurements can be retrieved from simpler standard spectrometry, allowing discussion of the influence of pattern depth, which determines the extraction by the photonic structure as compared to other uncontrolled pathways such as diffusion from defects in the film coating. These assessments provide a quick and safe method for the quantitative evaluation of light extraction strategies toward a rational design of light emitting devices with optimized properties. [ABSTRACT FROM AUTHOR]

In nanoimprint lithography (NIL) viscous flow in polymeric thin films is the primary mechanism for the generation and the relaxation of the structures. Here we quantify the impact of confinement on the flow rate. Pattern relaxation experiments were carried out above the glass transition temperature as a function of film thickness. The results are adequately fitted by a simple expression for the flow rate valid at all confinements. This expression, based on Newtonian viscosity, should be of use in NIL process design and for the measurement of the rheological properties of confined polymers. [ABSTRACT FROM AUTHOR]