Three-dimensional nanoscale imaging of polymer bulk-heterojunction by scanning electrical potential microscopy and C60 + cluster ion slicing
Journal
Analytical Chemistry
Journal Volume
81
Journal Issue
21
Pages
8936-8941
Date Issued
2009
Author(s)
Yu, B.-Y.
Lin, W.-C.
Huang, J.-H.
Chu, C.-W.
Lin, Y.-C.
Kuo, C.-H.
Lee, S.-H.
Shyue, J.-J.
Abstract
Solution-processable fullerene and copolymer bulk-heterojunctions are widely used as the active layer of solar cells. It is known that the controlled phase-separation in the film provides a pathway for carrier transportation and is crucial to efficiency. In this work, scanning electrical potential microscopy (SEPM) is used to examine the surface distribution of [6,6]phenyl-C61-butyric acid methyl ester and poly(3-hexylthiophene), which form the bulk-heterojunction. Because the two components have different energies in the highest occupied molecular orbital (HOMO), the differences in contact potential yield strong contrast in SEPM. A cluster ion beam (C60+) is used to remove the surface in order to determine the structure below, and SEPM is used to analyze the newly exposed surface. With the SEPM images acquired from different depth through the material stacked, a 3D volume image is obtained. It is demonstrated that using SEPM with cluster ion slicing is an effective tool for studying the 3D nanostructures of soft materials. © 2009 American Chemical Society.
SDGs
Other Subjects
Active Layer; Bulk heterojunction; Bulk-heterojunctions; Butyric acids; Carrier transportation; Cluster ion beams; Cluster ions; Contact potential; Effective tool; Electrical potential; Highest occupied molecular orbital; Methyl esters; Nano-scale imaging; Poly (3-hexylthiophene); Polymer bulk; Processable; Soft material; Strong contrast; Surface distributions; Two-component; Volume image; Esters; Fatty acids; Fullerenes; Heterojunctions; Ions; Molecular orbitals; Phase separation; Photovoltaic cells; Surfaces; Three dimensional; [6,6]phenyl c61 butyric acid methyl ester; nanomaterial; poly(3 hexylthiophene); polymer; unclassified drug; article; chemical structure; electric potential; energy; image analysis; nanoanalysis; nanoimaging; orbit; phase separation; scanning electrical potential microscopy; surface property; three dimensional imaging
Type
journal article