External quantum efficiency above 100% in a singlet-exciton-fission-based organic photovoltaic cell.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 23599489.
- Also identified by DOI 10.1126/science.1232994.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Singlet exciton fission transforms a molecular singlet excited state into two triplet states, each with half the energy of the original singlet. In solar cells, it could potentially double the photocurrent from high-energy photons. We demonstrate organic solar cells that exploit singlet exciton fission in pentacene to generate more than one electron per incident photon in a portion of the visible spectrum. Using a fullerene acceptor, a poly(3-hexylthiophene) exciton confinement layer, and a conventional optical trapping scheme, we show a peak external quantum efficiency of (109 ± 1)% at wavelength λ = 670 nanometers for a 15-nanometer-thick pentacene film. The corresponding internal quantum efficiency is (160 ± 10)%. Analysis of the magnetic field effect on photocurrent suggests that the triplet yield approaches 200% for pentacene films thicker than 5 nanometers.