RIKEN Center for Emergent Matter Science Emergent Functional Polymers Research Team

Team Director: Keisuke Tajima (Ph.D.)

Japanese Page

Research Summary

We work on the development of new organic semiconducting polymer materials and their application to organic electronic devices. Specifically, we seek the methodology and the molecular design to control the precise structures in molecular- and nano-scale at our will, and try to find breakthroughs to drastically enhance the performance of the organic electronic devices. Targets of our research are not only the conventional organic solar cells and field-effect transistors, but also the organic electronic devices with new functions based on the structure controls.

Main Research Fields

Chemistry

Related Research Fields

Engineering

Keywords

Organic solar cells
Semiconducting organic polymers
Thin films
Nanostructures
Interfacial science

Selected Publications

1. Yokoyam, T. and Tajima, K.:
"Surface Segregated Monolayers of Fluoroalkylated Rod-like Molecule for Asymmetric Charge Transport at Organic Semiconductor Interfaces"
ACS Appl. Electron. Mater. 6, 4570 (2024).
2. Nakano, K., Kaji, Y. and Tajima, K.:
"Origin of Electric Field-dependent Charge Generation in Organic Photovoltaics with Planar and Bulk Heterojunctions"
J. Mater. Chem. A 11, 26499 (2023).
3. Nakano, K., Leong, I. W., Hashizume, D., Bulgarevich, K., Takimiya, K., Nishiyama, Y., Yamazaki, T. and Tajima, K.:
"Synthesis of 3,3′- Dihydroxy-2,2′-diindan-1,1′-dione Derivatives for Tautomeric Organic Semiconductors Exhibiting Intramolecular Double Proton Transfer"
Chem. Sci. 14, 12205 (2023).
4. Suzuki, R., Ochiai, Y., Nakano, K., Miyasaka, M. and Tajima, K.:
"Detrimental Effects of “Universal" Singlet Photocrosslinkers in Organic Photovoltaics"
ACS Appl. Energy Mater. 6, 4982 (2023).
5. Wang, W.-C., Nakano K., Hsu, C.-S. and Tajima, K.:
"Synthesis of 2,5,8-Tris(1-phenyl-1H-benzo[d]imidazol-2-yl) benzo[1,2-b:3,4-b′:5,6-b″] Trithiophenes and Their Spontaneous Orientation Polarization in Thin Films"
ACS Appl. Mater. Interfaces 15, 20294 (2023).
6. Nakano, K., Kaji, Y. and Tajima, K.:
"Impact of Narrowing Density of States in Semiconducting Polymers on Performance of Organic Field-Effect Transistors"
Small 19, 2205570 (2022).
7. Chen, F., Nakano, K., Kaji, Y. and Tajima, K.:
"Design of Planar-Zigzag Semiconducting Polymers to Control Chain Orientation and Electronic Structure for Organic Photovoltaics"
Mater. Chem. Front. 6, 3062 (2022).
8. Wang, W.-C., Nakano, K., Hashizume, D., Hsu, C.-S. and Tajima, K.:
"Tuning Molecular Conformations to Enhance Spontaneous Orientation Polarization in Organic Thin Films"
ACS Appl. Mater. Interfaces 14, 18773 (2022).
9. Wang, C., Hao, H. and Tajima, K.:
"Essential Role of Triplet Diradical Character for Large Magnetoresistance in Quinoidal Organic Semiconductor with High Electron Mobility"
Adv. Sci. 9, 2201045 (2022).
10. Nakano, K., Chen, F., Kaji Y. and Tajima, K.:
"Control of molecular orientations by sequential deposition to enhance organic photovoltaic performance"
Mater. Chem. Phys. 281, 125849 (2022).