Exciton diffusion length in narrow bandgap polymers
Year: 2012
Type: article
Abstract: We developed a new method to accurately extract the singlet exciton diffusion length in organic semiconductors by blending them with a low concentration of methanofullerene[6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The dependence of photoluminescence (PL) decay time on the fullerene concentration provides information on both exciton diffusion and the nanocomposition of the blend. Experimentally measured PL decays of blends based on two narrow band gap dithiophene–benzothiadiazole polymers, C–PCPDTBT and Si–PCPDTBT, were modeled using a Monte Carlo simulation of 3D exciton diffusion in the blend. The simulation software is available for download. The extracted exciton diffusion length is 10.5 ± 1 nm in both narrow band gap polymers, being considerably longer than the 5.4 ± 0.7 nm that was measured with the same technique in the model compound poly(3-hexylthiophene) as a reference. Our approach is simple, fast and allows us to systematically measure and compare exciton diffusion length in a large number of compounds.
Source: Energy & Environmental Science
DOI: 10.1039/c2ee03466b
Authors: Oleksandr V. Mikhnenko, Hamed Azimi, Markus Scharber, Mauro Morana, Paul W. M. Blom, Maria Antonietta Loi
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2103467181