[19a-Z31-1~11] 17.3 Layered materials

▲ [19a-Z31-7] Photo Enhanced Electrical Properties of Organic Dye Doped MoS₂ FET Sensor

〇(DC)Md Iftekharul Alam¹, Tsuyoshi Takaoka¹, Hiroki Waizumi¹, M. Shamim Al Mamun¹, Yudai Tanaka¹, Kosei Takahashi¹, Tadahiro Komeda², Atsushi Ando³ (1.Tohoku Univ., 2.IMRAM, Tohoku Univ., 3.Nanoelectronics Research Institute, AIST)

Keywords:MoS2,FET,Methylene blue, Photo current,n-doping,charge transfer

The MoS₂ is a proclaimed candidate for a channel material of the FET sensor due to its significant electrical and optoelectrical properties like the high on-off ratio and carrier mobility, in addition to the high sensitivity to the light injection. It is expected that pi(π) conjugated organic dye molecules like methylene blue(MB) when adsorbed on MoS₂ FETenhance such a photoresponse behavior under light injection.We focus on how the electrical properties of MoS₂ FET doped with the MB molecule changes with the light illumination. Two maximum photocurrent peaks in were observed between 600nm and 670nm for all cases. An additional shoulder is appeared at around 500nm wavelength that is absent in pristine MoS₂ FET under light injection. That maximum photocurrent enhancement is due to the charge transfer from the LUMO of MB to the conduction band of MoS₂ while the additional shoulder can be attributed by the formation of S bond S or S bond Mo coordination interaction with MoS₂.