Issue 4, 2013

Physical mixtures of small-molecule and polymeric organic semiconductors: comparing thermodynamic behavior and thin-film structure

Abstract

Physical mixtures of organic semiconductors are increasingly used for the development of new materials in thin film, organic electronic applications and their electronic properties are strongly affected by their morphology. Here, we report on studies of blends of an electron-donating small molecule, BTD-DTP, with the electron-acceptor polymer PNDI-2T and the correlations between their thermal behaviour, intermixing and thin film structure. A significant depression of the PNDI-2T melting point (ΔT = 111 °C) is observed upon increasing the small molecule content. Grazing incidence X-ray scattering (GIXS) and scanning probe microscopy (SPM) of thin films of varying composition show an increase in the small molecule crystalline phase and reduction in the crystallite orientation distribution, as the small molecule to polymer ratio reaches ∼50 : 50 wt. The domain sizes of the small molecule and polymer crystalline phases reach a minimum at the 50 : 50 wt ratio as well, suggesting the formation of the phases leads to mutual limitation of their crystalline domain size. Comparison of the bulk and thin film properties shows a divergence in behaviour of the small molecule, which in the bulk exhibits only a monotonic decrease in melting point with addition of polymer, but which has an increase in crystallinity, from 20 to 50 wt% PNDI-2T content.

Graphical abstract: Physical mixtures of small-molecule and polymeric organic semiconductors: comparing thermodynamic behavior and thin-film structure

Supplementary files

Article information

Article type
Paper
Submitted
18 Jun 2012
Accepted
12 Nov 2012
First published
27 Nov 2012

J. Mater. Chem. C, 2013,1, 778-785

Physical mixtures of small-molecule and polymeric organic semiconductors: comparing thermodynamic behavior and thin-film structure

B. H. Wunsch, K. Kim, Y. Rho, B. Ahn, S. Jung, L. E. Polander, D. G. Bucknall, S. R. Marder and M. Ree, J. Mater. Chem. C, 2013, 1, 778 DOI: 10.1039/C2TC00613H

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