Jump to main content
Jump to site search

Issue 1, 2019
Previous Article Next Article

Multi-length scale morphology of nonfullerene all-small molecule blends and its relation to device function in organic solar cells

Author affiliations

Abstract

Nonfullerene all-small molecule organic solar cells (OSCs) have attracted significant attention due to their competitive performance compared to the well-studied polymer-based OSCs. Small molecules are considered to be materials of choice for industrial scale OSC production due to their relatively high purity, reproducibility, and well-defined molecular weights. Despite the recent progress in all-small molecule solar cells, the mesoscale morphology of these devices remains elusive. A fundamental understanding of the structure–property relationships of these systems is thus critical for further device performance enhancement. Here, we report a dramatic change in device performance of a nonfullerene all-small molecule bulk heterojunction system upon changing the side chains of the electron donor small molecules. Morphology analysis via resonant soft X-ray scattering shows that the average composition variation and the size of the smaller domains of the all-small molecule blends are the most influential factors that derive the photogeneration and collection efficiency of charges in efficient all-small molecule OSCs. The observed side-chain and processing initiated morphological changes resulted in distinct device efficiencies in these systems. Despite the fact that side chains are mainly meant to facilitate material dissolution, the current study clearly shows that they can also impose a significant effect on material organization and photovoltaic properties. The findings will give a clear understanding of the role of side chains and processing in material organization and device functionality, and the knowledge gained in this study is quite crucial in designing next-generation materials and devices.

Graphical abstract: Multi-length scale morphology of nonfullerene all-small molecule blends and its relation to device function in organic solar cells

Back to tab navigation

Supplementary files

Article information


Submitted
02 Oct 2018
Accepted
19 Nov 2018
First published
19 Nov 2018

Mater. Chem. Front., 2019,3, 137-144
Article type
Research Article
Author version available

Multi-length scale morphology of nonfullerene all-small molecule blends and its relation to device function in organic solar cells

I. Angunawela, L. Ye, H. Bin, Z. Zhang, A. Gadisa, Y. Li and H. Ade, Mater. Chem. Front., 2019, 3, 137
DOI: 10.1039/C8QM00503F

Social activity

Search articles by author

Spotlight

Advertisements