Polarized emission from stretched PPV films viewed at the molecular level

文献情報

出版日 2015-07-08

DOI 10.1039/C5CP02513C

インパクトファクター 3.676

著者

Rodrigo Ramos, Melissa F. Siqueira, Thiago Cazati, Roberto M. Faria, Marilia J. Caldas

原文を見る

要旨

We present a study on the photoluminescence (PL) of thin films of poly-(p-phenylene vinylene) (PPV), non-stretched and uniaxially stretched. The experimental study was carried out using linear polarized light as the excitation beam, oriented either parallel or perpendicular to the stretch axis (S). The results showed that when the excitation light source has polarization perpendicularly oriented to the stretch direction, the emitted PL presents maximum intensity in the orientation S, and a minimum in the direction orthogonal to S. In order to understand this interesting phenomenon, we employ theoretical simulations at the atomistic level. We use classical molecular dynamics to simulate amorphous PPV films, non-stretched and stretched, from which we find a tendency of overall alignment of PV units to S, and of local clustering in herring-bone and π-stacking partial symmetries. Our study of optical activity of these kinds of clusters, performed through a quantum semi-empirical method, allows us to explain this polarization conversion behavior, and indicates the possibility of using underivatized PPV as the active layer for polarized electroluminescent devices.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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