Influence of Molecular Weight on the Performance of Organic Solar Cells Based on a Fluorene Derivative

• The performance of organic photovoltaic (OPV) bulk-heterojunction blends comprising a liquid-crystalline fluorene derivative and a small-molecular fullerene is found to increase asymptotically with the degree of polymerization of the former. Similar to various thermodynamic transition temperatures as well as the light absorbance of the fluorene moiety, the photocurrent extracted from OPV devices is found to strongly vary with increasing oligomer size up to a number average molecular weight, M-n approximate to 10 kg mol(-1), but is rendered less chain-length dependent for higher M-n as the fluorene derivative gradually adopts polymeric behavior.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Keyword

thermotropic alignment

morphology

thin-films

polyfluorene copolymer/fullerene blends

field-effect transistors

liquid-crystalline

dependence

polyfluorene

charge-transport

open-circuit voltage

polymer

TECHNOLOGY

Publication and Content Type

art (subject category)

ref (subject category)