Jump to main content
Jump to site search

Issue 5, 2014
Previous Article Next Article

Consequences of hydrogen bonding on molecular organization and charge transport in molecular organic photovoltaic materials

Author affiliations

Abstract

Reported is a systematic molecular structure–property relationship study to evaluate the consequences of dedicated H-bonding interactions between molecular electron donors on molecular assembly, absorption, charge collection, and performance in small-molecule bulk heterojunction organic photovoltaic devices. Three families of branched quaterthiophene donor chromophores have been synthesized with members that share nearly identical electronic and optical properties in the molecularly dispersed state but are either capable or incapable of self-association by hydrogen bonding (H-bonding). Phthalhydrazide-functionalized quaterthiophenes are H-bond “active” and show signatures of H-bond promoted assembly in solution (by 1H NMR) and in both neat and blended (with C60) films (by IR). Compared to control compounds with H-bonding “turned off”, the H-bonded derivatives show red-shifted thin film absorption (neat and as blends with C60), different colors as bulk solids, and increased decomposition and melt temperatures. Photovoltaic devices made from blends of H-bonded donor molecules with C60 as the electron acceptor show improved charge collection length and external quantum efficiency resulting in a more than two-fold enhancement in power conversion efficiency relative to non-H-bonding controls, from 0.49% to 1.04%. We anticipate this approach could be generalized to include other donor chromophores with lower optical gap to harvest more longer-wavelength photons and achieve higher power conversion efficiencies.

Graphical abstract: Consequences of hydrogen bonding on molecular organization and charge transport in molecular organic photovoltaic materials

Back to tab navigation

Supplementary files

Article information


Submitted
04 Sep 2013
Accepted
02 Dec 2013
First published
04 Dec 2013

J. Mater. Chem. A, 2014,2, 1541-1549
Article type
Paper

Consequences of hydrogen bonding on molecular organization and charge transport in molecular organic photovoltaic materials

B. M. Schulze, N. T. Shewmon, J. Zhang, D. L. Watkins, J. P. Mudrick, W. Cao, R. Bou Zerdan, A. J. Quartararo, I. Ghiviriga, J. Xue and R. K. Castellano, J. Mater. Chem. A, 2014, 2, 1541
DOI: 10.1039/C3TA13529B

Social activity

Search articles by author

Spotlight

Advertisements