A few layers graphene-based phototransistor was fabricated and investigated. Graphene layers were mechanically exfoliated and transferred into a p-doped Si/SiO₂ substrate to fabricate a graphene field effect transistor. Gold electrodes were deposited to create a drain and source to the graphene and a back contact gate to the p-doped silicon. The device performance was examined by measuring the current-voltage characteristics in the dark and under illumination. At zero drain voltage bias and room temperature, the device operated and achieved high responsivity and detectivity on the order of 2.7נ10⁴ A W⁻¹ and 5נ10¹² cmHz^0.5/W, respectively. A ratio of 29 between the photocurrent and the dark current was achieved. The device shows an excellent tunable photoresponse as a function of the applied back-gate voltage, which indicates the domination of a photogating effect produced by the Si/SiO₂ substrate.

制备并研究了几层基于石墨烯的光电晶体管。将石墨烯层机械剥离并转移到p掺杂的Si / SiO ₂衬底中，以制造石墨烯场效应晶体管。沉积金电极以产生石墨烯的漏极和源极以及产生p掺杂硅的背接触栅极。通过在黑暗和光照下测量电流-电压特性来检查器件性能。在零漏极电压偏置和室温下，该器件工作并获得了高响应度和高检测率，分别为2.7×10 ⁴ AW ^-1和5 × 10 ¹² cmHz ^0.5/ W。光电流与暗电流之比达到29。该器件根据施加的背栅电压显示出极好的可调光响应，表明由Si / SiO ₂衬底产生的光选通效应占优势。