Abstract
For the photoelectric conversion layer that converts light energy and electric energy, the thickness of using organic pigments as a photoelectric conversion layer has usually been limited to a thickness on the order of nm. This is because when the photoelectric conversion layer is prepared by mixing the organic pigment, the electric resistance often increases. For example, in organic light-emitting diodes that have been used for large-screen TVs and mobile phone displays in recent years, and in organic photovoltaic cells (OPVs) that are expected to be one of the next-generation solar cells, the thickness of organic pigments is usually several tens of nm. The thickness of OPVs that use organic polymers instead of organic pigments often exceeds several hundred nm. In both material systems, only a small number of examples of normal operation with thickness close to 1 µm (=1,000 nm) are reported. Although it is principally clear that, as the thickness increases, the proportion of light that can be absorbed increases and the current that can be generated increases, this simple relation has not been demonstrated with real OPV devices due to the difficulty to fabricate thick OPVs. This chapter introduces that if an organic pigment is properly crystallized, it can be used as a photoelectric conversion layer of an OPV even if it is thickened to 10 µm, and this chapter also introduces a demonstration of the relationship in which the light absorbed by the pigment and the generated current correspond in a neat manner in a wide range of thickness (40 nm–1 µm).
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09 March 2021
In the original version of the book, the following chapters corrections have been incorporated:
The erratum chapters and book have been updated with the changes.
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Acknowledgments
This section is written based on the results of collaboration with Mr. Mikimasa Katayama (at that time) at Tokyo University of Agriculture and Technology, and Professor Masahiro Hiramoto and Dr. Satoshi Nakao (at that time) at the Institute for Molecular Science. We would like to thank Professor C.W. Tang and Assistant Professor S. Dong at Hong Kong University of Science and Technology for their discussion and advices. In addition, part of the research introduced in this section was carried out with the support of JST-ALCA, JSPS Scientific Research Fund (17H04807), and Nanotechnology Platform Project (Molecular/Material Synthesis).
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Kaji, T. (2021). OPV with a Crystalline Organic Pigment Active Layer Up to 10 μm. In: Hiramoto, M., Izawa, S. (eds) Organic Solar Cells. Springer, Singapore. https://doi.org/10.1007/978-981-15-9113-6_4
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DOI: https://doi.org/10.1007/978-981-15-9113-6_4
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