Koichi Wakita
Chubu University
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Publication
Featured researches published by Koichi Wakita.
photovoltaic specialists conference | 2012
Golap Kalita; Koichi Wakita; Masayoshi Umeno; Yasuhiko Hayashi; Masaki Tanemura
Indium tin oxide (ITO) and related oxide based materials have been widely used as transparent electrode in optoelectronic devices and organic solar cells. Here, we demonstrate application of chemical vapor deposited (CVD) graphene films as transparent electrode for organic solar cells. Large area graphene films are deposited by control pyrolysis of botanical derivative camphor (C10H16O) and transparent electrode were fabricated by direct synthesis or transfer process. Raman spectroscopy and transmission electron microcopy studies are used to characterize the synthesized graphene based materials. Direct synthesized and transferred graphene films on glass or plastic substrates show very good optical transparency, electrical conductivity and mechanical stability. P3HT:PCBM bulk heterojunction solar cells are fabricated successfully on graphene based transparent electrode and compared with ITO based device. The dark light characteristic shows very good rectification with minimum leakage current. Under illumination of light the device shows very good open circuit voltage, short circuit current density and conversion efficiency.
ieee international nanoelectronics conference | 2013
Golap Kalita; Koichi Wakita; Masayoshi Umeno; Yasuhiko Hayashi; Masaki Tanemura
We demonstrate synthesis of large area graphene on a metal (Ni and Cu) foil by the thermal chemical vapor deposition (CVD) process using the solid camphor (C10H16O) as a carbon source. The graphene growth process on a polycrystalline metal foil significantly influence by the gas composition and quantity of solid precursor. Synthesis of high quality continuous graphene film is achieved in the developed technique. Fully flexible transparent conductor is fabricated by transferring the graphene film on a plastic substrate.
Physica Status Solidi (a) | 2012
Golap Kalita; Subash Sharma; Koichi Wakita; Masayoshi Umeno; Yasuhiko Hayashi; Masaki Tanemura
Journal of Surface Engineered Materials and Advanced Technology | 2013
Sudip Adhikari; Madhu Sudan Kayastha; Dilip Chandra Ghimire; Hare Ram Aryal; Sunil Adhikary; T. Takeuchi; K. Murakami; Y. Kawashimo; Hideo Uchida; Koichi Wakita; Masayoshi Umeno
Optical and Quantum Electronics | 2013
Durga Prasad Sapkota; Madhu Sudan Kayastha; Koichi Wakita
Journal of the American Ceramic Society | 2013
Makoto Takahashi; Kengo Sawada; Hiroyuki Ishikawa; Tatsunosuke Omi; Sadao Ohkido; Masahiro Tahashi; Koichi Wakita
Electronics Letters | 2013
Madhu Sudan Kayastha; Durga Parsad Sapkota; Makoto Takahashi; Koichi Wakita
Journal of Nanoscience and Nanotechnology | 2014
Masahiro Matsushima; Golap Kalita; Kimitoshi Kato; M. Noda; Hideo Uchida; Koichi Wakita; Masayoshi Umeno; Masaki Tanemura
World Academy of Science, Engineering and Technology, International Journal of Electronics and Communication Engineering | 2015
Durga Prasad Sapkota; Madhu Sudan Kayastha; Koichi Wakita
Optical and Quantum Electronics | 2015
Durga Prasad Sapkota; Madhu Sudan Kayastha; Koichi Wakita