Fast response infrared photodetector based on reduced graphene oxide

• Main Authors: Ahmad, Harith, Tajdidzadeh, Mojgan, Ismail, Mohammad Faizal, Thandavan, Tamil Many K.
• Format: Article
• Published: Natl Inst Optoelectronics 2020
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/36827/

A fast-response-infrared-reduced graphene oxide (rGO) photodetector was prepared via drop casting. A silver (Ag) source and 50 mm-thick drain electrodes were deposited to obtain an active channel of 5 mm x 2 mm dimension. The Schottky contacts among the rGO semiconducting layer, Ag source, and drain electrodes enabled the efficient transfer of photo-generated charge carriers. The photodetector showed high sensitivity toward a laser illumination wavelength of 974 nm. Current-voltage characteristics showed low sensitivity in the negative bias region, but a significantly high response was attained at increased laser power levels. Photoresponsivity and external quantum efficiency (EQE) were determined at different laser power levels ranging from 7.64 mW to 121.70 mW. The highest EQE was obtained at the lowest laser power level of 7.64 mW. Fast response and recovery time were achieved at 4.01 and 96.28 mu s, respectively, at laser frequency modulation of 5000 Hz, although the photoresponsivity remains low.