Publications by authors named "Luana Wouk"

In this paper, the effect of a silafluorene derivative copolymer, the poly[2,7-(9,9-dioctyl-dibenzosilole)-alt-4,7-bis(thiophene-2-yl)benzo-2,1,3-thiadiazole] (PSiF-DBT) sensitized by a simpler homopolymer, the poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) were investigated in a bilayer and ternary blend configuration. The energy transfer between the polymers prior to electron transfer to the acceptors can be an efficient alternative to photocurrent improvement in photovoltaic devices. The interactions between the two donor polymer films were evaluated optically and morphologically with several experimental techniques and correlated to the photovoltaic performance.

View Article and Find Full Text PDF

In this study, we investigate two copolymers as electron donors in photovoltaic devices, PFO-DBT (poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole]) and its analogue with Si, PSiF-DBT (poly[2,7-(9,9-dioctyl-dibenzosilole)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole]). The results discussed here are related to the influence of heavy atoms on the electrical and morphological properties of the devices. Charge transfer dynamics in the polymeric films were evaluated using the core-hole clock method.

View Article and Find Full Text PDF

Organic photovoltaic (OPV) devices have reached high power conversion efficiencies, but they are usually processed using halogenated toxic solvents. Hence, before OPV devices can be mass-produced by industrial processing, it would be desirable to replace those solvents with eco-friendly ones. Theoretical tools may be then a powerful ally in the search for those new solvents.

View Article and Find Full Text PDF