Search

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]

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]