Issue 1, 2016

Open circuit voltage and efficiency in ternary organic photovoltaic blends

Abstract

Organic bulk heterojunction solar cells based on ternary blends of two donor absorbers and one acceptor are investigated by experiments and modeling. The commonly observed continuous tunability of the open circuit voltage VOC with the donor1 : donor2 ratio can quantitatively be explained as quasi-Fermi level splitting due to photocreated charges filling a joint density of states that is broadened by Gaussian disorder. On this basis, a predictive model for the power conversion efficiency that accounts for the composition-dependent absorption and the shape of the current–voltage characteristic curve is developed. When all other parameters, most notably the fill factor, are constant, we find that for state-of-the-art absorbers, having a broad and strong absorption spectrum, ternary blends offer no advantage over binary ones. For absorbers with a more narrow absorption spectrum ternary blends of donors with complementary absorption spectra, offer modest improvements over binary ones. In contrast, when, upon blending, transport and/or recombination kinetics are improved, leading to an increased fill factor, ternaries may offer significant advantages over binaries.

Graphical abstract: Open circuit voltage and efficiency in ternary organic photovoltaic blends

Supplementary files

Article information

Article type
Paper
Submitted
09 Oct 2015
Accepted
19 Nov 2015
First published
19 Nov 2015

Energy Environ. Sci., 2016,9, 257-266

Author version available

Open circuit voltage and efficiency in ternary organic photovoltaic blends

N. Felekidis, E. Wang and M. Kemerink, Energy Environ. Sci., 2016, 9, 257 DOI: 10.1039/C5EE03095A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements