Photodetection in p–n junctions formed by electrolyte-gated transistors of two-dimensional crystals
Type
ArticleAuthors
Kozawa, DaichiPu, Jiang
Shimizu, Ryo
Kimura, Shota
Chiu, Ming-Hui

Matsuki, Keiichiro
Wada, Yoshifumi
Sakanoue, Tomo
Iwasa, Yoshihiro
Li, Lain-Jong

Takenobu, Taishi
KAUST Department
Material Science and Engineering ProgramPhysical Science and Engineering (PSE) Division
Date
2016-11-16Online Publication Date
2016-11-16Print Publication Date
2016-11-14Permanent link to this record
http://hdl.handle.net/10754/621925
Metadata
Show full item recordAbstract
Transition metal dichalcogenide monolayers have attracted much attention due to their strong light absorption and excellent electronic properties. These advantages make this type of two-dimensional crystal a promising one for optoelectronic device applications. In the case of photoelectric conversion devices such as photodetectors and photovoltaic cells, p–n junctions are one of the most important devices. Here, we demonstrate photodetection with WSe2 monolayer films. We prepare the electrolyte-gated ambipolar transistors and electrostatic p–n junctions are formed by the electrolyte-gating technique at 270 K. These p-n junctions are cooled down to fix the ion motion (and p-n junctions) and we observed the reasonable photocurrent spectra without the external bias, indicating the formation of p-n junctions. Very interestingly, two-terminal devices exhibit higher photoresponsivity than that of three-terminal ones, suggesting the formation of highly balanced anion and cation layers. The maximum photoresponsivity reaches 5 mA/W in resonance with the first excitonic peak. Our technique provides important evidence for optoelectronics in atomically thin crystals.Citation
Kozawa D, Pu J, Shimizu R, Kimura S, Chiu M-H, et al. (2016) Photodetection in p–n junctions formed by electrolyte-gated transistors of two-dimensional crystals. Applied Physics Letters 109: 201107. Available: http://dx.doi.org/10.1063/1.4967173.Sponsors
D.K. acknowledges the support of the Grant-in-Aid for Encouragement of Young Scientists (B) (JSPS KAKENHI Grant No. JP 16K17485) from Japan Society for the Promotion of Science (JSPS). Y.W., J.P., and K.M. acknowledge the Leading Graduate Program in Science and Engineering, Waseda University, from JSPS. D.K. and J.P. were supported by the Grant-in-Aid for JSPS Fellows (JSPS KAKENHI Grant Nos. JP 15J07423 and JP 14J07485). T.S. is grateful to the Grant-in-Aid for Encouragement of Young Scientists (A) (JSPS KAKENHI Grant No. JP 26706012) from JSPS. T.T. was partially supported by the Funding Program for the Next Generation of World-Leading Researchers from JSPS, and Grants-in-Aid from MEXT (JSPS KAKENHI Grant Nos. JP 16K13618, JP 26102012 “π-System Figuration,” and JP 25000003 “Specially Promoted Research”).Publisher
AIP PublishingJournal
Applied Physics LettersarXiv
1611.01589ae974a485f413a2113503eed53cd6c53
10.1063/1.4967173