▎ 摘　　要

this work, a new Ultraviolet Optically Controlled Graphene Field-Effect Transistor (UV-OC-GFET) basedon Graded Band-Gap (GBG) ZnMgO photosensitive-gate is proposed. The device drain current model isnumerically developed by self-consistently solving the Schrodinger/Poisson equations based on nonequilibrium Green's function (NEGF) formalism. The influence of GBG strategy with different profiles onthe device sensing performances is analyzed. Our investigation reveals that the use of both GBG ZnMgOphotogate and graphene nanoribbon channel offers the dual-benefit of improved electric field distribution in the photosensitive layer and enhanced drain current. This leads to outperforming the deviceFigure of Merits (FoMs). In this context, it is found that the proposed UV sensor with optimized band-gapprofile exhibits giant responsivity exceeding 1.5 x 10(6)A/W with superb detectivity of 7 x 10(14) Jones, farsurpassing that of the conventional Si-channel based phototransistors. Therefore, this innovative strategy based on graphene nanoribbon channel combined with GBG sensitive-gate pinpoints a new pathtowards achieving high-performance visible-blind UV-phototransistor, making it a potential alternativephotoreceiver for chip-level optical communication and optoelectronic applications. (c) 2021 Elsevier B.V. All rights reserved.