▎ 摘　　要

Graphene oxide (GO) based heterojunction photodetector was fabricated using a simple drop casting method which was further heated in a furnace at 450 degrees C. The physical characterization of the fabricated photodetector revealed non-homogeneous GO layer and presence of D and G band of graphene respectively at 1357 and 1596 cm(-1). The photoresponsivity and external quantum efficiency of the photodetector were evaluated and optimized using infrared (IR) illumination at a wavelength of 974 nm. Current-voltage (I-V) characteristics found to be sturdily dependent on the increased laser power as it showed threshold voltage (V-th) at 0.855 V. High photoresponsivity 9.577 mAW(-1) was detected for laser power at 2.405 mW at direct-current (DC) bias 13.358 V. Rise and fall time found to be varying with frequency modulated laser and the applied DC bias voltage across the photodetector. High frequency modulation and low DC bias voltage showed profound rise and fall time at 48 and 2210 mu s respectively. The photodetector was highly sensitive to 974 nm IR illumination for modulated laser frequency ranging from 1000 to 5000 Hz. Besides that, the fabricated heterojunction photodetector able to function in good condition at low DC bias voltage.