Nanoscale Morphology of Doctor Bladed versus Spin-Coated Organic Photovoltaic Films

Pokuri BSS, Sit J, Wodo O, Baran D, Ameri T, Brabec C, Moule AJ, Ganapathysubramanian B (2017)


Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2017

Journal

Pages Range: 1701269--n/a

Article Number: 1701269

DOI: 10.1002/aenm.201701269

Abstract

Recent advances in efficiency of organic photovoltaics are driven by judicious
selection of processing conditions that result in a “desired” morphology.
An important theme of morphology research is quantifying the effect of
processing conditions on morphology and relating it to device efficiency.
State-of-the-art morphology quantification methods provide film-averaged or
2D-projected features that only indirectly correlate with performance, making
causal reasoning nontrivial. Accessing the 3D distribution of material, however,
provides a means of directly mapping processing to performance. In this
paper, two recently developed techniques are integrated—reconstruction of
3D morphology and subsequent conversion into intuitive morphology descriptors
—to comprehensively image and quantify morphology. These techniques
are applied on films generated by doctor blading and spin coating, additionally
investigating the effect of thermal annealing. It is found that morphology
of all samples exhibits very high connectivity to electrodes. Not surprisingly,
thermal annealing consistently increases the average domain size in the
samples, aiding exciton generation. Furthermore, annealing also improves
the balance of interfaces, enhancing exciton dissociation. A comparison of
morphology descriptors impacting each stage of photophysics (exciton generation,
dissociation, and charge transport) reveals that spin-annealed sample
exhibits superior morphology-based performance indicators. This suggests
substantial room for improvement of blade-based methods (process optimization)
for morphology tuning to enhance performance of large area devices.

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How to cite

APA:

Pokuri, B.S.S., Sit, J., Wodo, O., Baran, D., Ameri, T., Brabec, C.,... Ganapathysubramanian, B. (2017). Nanoscale Morphology of Doctor Bladed versus Spin-Coated Organic Photovoltaic Films. Advanced Energy Materials, 1701269--n/a. https://dx.doi.org/10.1002/aenm.201701269

MLA:

Pokuri, Balaji Sesha Sarath, et al. "Nanoscale Morphology of Doctor Bladed versus Spin-Coated Organic Photovoltaic Films." Advanced Energy Materials (2017): 1701269--n/a.

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