Chapter 3
Percolation Toward Lateral Junctions
Masahiro Hiramoto
3.1 Motivation
Blended junctions are commonly used for modern organic solar cells [1–8]. Conventional organic solar cells are vertically built on indium tin oxide (ITO) glass substrates
using a sandwich-type structure [9–11]. However, the nanostructure fabrication of
the electron and hole transport routes in the blended donor (D) and acceptor (A)
molecules developed by percolation is still a problem in spite of recent reports
on blended systems where the thickness reached nearly a micron [6, 12–14]. To
determine fundamental resolutions, we have demonstrated various new principles of
donor/acceptor (D/A) junctions acting as alternative blended junctions.
This Chapter summarizes the junctions based on percolation (Sect. 3.2), vertical
multilayers (Sect. 3.3), and lateral multilayers (Sect. 3.4).
3.2 Percolation
This section summarizes percolated junctions with crystalline–amorphous nanocomposite structures, which are formed by controlling the substrate temperature during
the co-deposition of fullerene (C 60 ) and metal-free phthalocyanine (H 2 Pc) [15, 16].
M. Hiramoto (B)
National Institutes of Natural Sciences, Institute for Molecular Science, 5-1 Higashiyama
Myodaiji, Okazaki 444-8787 Aichi, Japan
e-mail: hiramoto@ims.ac.jp
© Springer Nature Singapore Pte Ltd. 2021
M. Hiramoto and S. Izawa (eds.), Organic Solar Cells,
https://doi.org/10.1007/978-981-15-9113-6_3
45
Percolation Toward Lateral Junctions
Masahiro Hiramoto
3.1 Motivation
Blended junctions are commonly used for modern organic solar cells [1–8]. Conventional organic solar cells are vertically built on indium tin oxide (ITO) glass substrates
using a sandwich-type structure [9–11]. However, the nanostructure fabrication of
the electron and hole transport routes in the blended donor (D) and acceptor (A)
molecules developed by percolation is still a problem in spite of recent reports
on blended systems where the thickness reached nearly a micron [6, 12–14]. To
determine fundamental resolutions, we have demonstrated various new principles of
donor/acceptor (D/A) junctions acting as alternative blended junctions.
This Chapter summarizes the junctions based on percolation (Sect. 3.2), vertical
multilayers (Sect. 3.3), and lateral multilayers (Sect. 3.4).
3.2 Percolation
This section summarizes percolated junctions with crystalline–amorphous nanocomposite structures, which are formed by controlling the substrate temperature during
the co-deposition of fullerene (C 60 ) and metal-free phthalocyanine (H 2 Pc) [15, 16].
M. Hiramoto (B)
National Institutes of Natural Sciences, Institute for Molecular Science, 5-1 Higashiyama
Myodaiji, Okazaki 444-8787 Aichi, Japan
e-mail: hiramoto@ims.ac.jp
© Springer Nature Singapore Pte Ltd. 2021
M. Hiramoto and S. Izawa (eds.), Organic Solar Cells,
https://doi.org/10.1007/978-981-15-9113-6_3
45