Graphene and PbS quantum dot hybrid vertical phototransistor.
A field-effect phototransistor based on a graphene and lead sulfide quantum dot (PbS QD) hybrid in which PbS QDs are embedded in a graphene matrix has been fabricated with a vertical architecture through a solution process. The n-type Si/SiO2substrate (gate), Au/Ag nanowire transparent source electrode, active layer and Au drain electrode are vertically stacked in the device, which has a downscaled channel length of 250 nm. Photoinduced electrons in the PbS QDs leap into the conduction band and fill in the trap states, while the photoinduced holes left in the valence band transfer to the graphene and form the photocurrent under biases from which the photoconductive gain is evaluated. The graphene/QD-based vertical phototransistor shows a photoresponsivity of 2 × 103A W-1, and specific detectivity up to 7 × 1012Jones under 808 nm laser illumination with a light irradiance of 12 mW cm-2. The solution-processed vertical phototransistor provides a new facile method for optoelectronic device applications.
Institute of Laser & Opto-electronics, College of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People's Republic of China. Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin 300072, People's Republic of China.
Xiaoxian
X
Song
Yating
Y
Zhang
Haiting
H
Zhang
Yu
Y
Yu
Mingxuan
M
Cao
Yongli
Y
Che
Haitao
H
Dai
Junbo
J
Yang
Xin
X
Ding
Jianquan
J
Yao