Graphene–Silicon-Based High-Sensitivity and Broadband Phototransistor

Graphene-silicon vertical junction is utilized here for fabrication of high-responsivity and broadband phototransistor. Graphene-silicon as a Schottky junction plays the role of collector-base junction in a bipolar junction phototransistor. We propose graphene-silicon-based phototransistor as a promising candidate for fabrication of high-gain photodetector with responsivity as high as 11 A/W. Gain and ON/OFF ratio of our fabricated device reach up to 18 and 100, respectively. Our results show that the graphene-silicon-based phototransistor is sensitive to a broad range of incident light from visible to IR spectrum. Our results open up a way to fabricate highly sensitive photodetectors suitable for silicon integrated electronics.