The heterojunction integration of two-dimensional(2D)materials via van der Waals(vdW)forces,unencumbered by lattice and processing constraints,constitutes an efficacious approach to enhance the overall optoelectronic ...The heterojunction integration of two-dimensional(2D)materials via van der Waals(vdW)forces,unencumbered by lattice and processing constraints,constitutes an efficacious approach to enhance the overall optoelectronic performance of photodetectors,due to an assortment of distinctive light-matter interactions.Nonetheless,vdW heterojunction photodetectors based on transition metal dichalcogenides(TMDs)face an inevitable trade-off between low dark currents and high responsivity,curtailing the application potential of myriad novel optoelectronic components in sensing,spectral,and communication systems.In this study,we present the successful actualization of a highly sensitive,self-powered,and gate-tunable bipolar response photodetector.The mechanisms underlying photocurrent generation were scrutinized via bias-,power-,and position-dependent mapping photoresponse measurements,identifying the photovoltaic effect,which is attributable to the Schottky junction’s built-in electric field,as the predominant mechanism.The prototype Au-WS2-graphene photodetector exhibits a remarkable light on/off ratio of 1.2×10^(6),a specific detectivity of 6.12×10^(11)cm H^(z1/2)W^(-1)with 20μs response time at 638 nm.The wide gate-tunable responsivity provides an adjustability scope,ranging from 0.9 to 3.1 A W^(-1).Notably,the device demonstrates an exceptional linear photocurrent response,with a linear dynamic range(LDR)value approximating 130 dB,which significantly surpasses that of other photodetectors based on TMDs.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62305077,62222514,61991440,and 62005249)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.Y2021070)+8 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB43010200)Shanghai Rising-Star Program(Grant No.20QA1410400)Shanghai Science and Technology Committee(Grant Nos.23ZR1482000,20JC1416000,and 22JC1402900)the Natural Science Foundation of Zhejiang Province(Grant No.LR22F050004)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Hangzhou West Science and Technology Innovation Corridor Youth ProjectExcellent Postdoctoral Research Projects of Zhejiang Province(Grant No.ZJ2021019)the Open Fund of State Key Laboratory of Infrared Physics(Grant No.SITP-NLIST-YB-2023-13)Zhejiang Provincial Natural Science Foundation(Grant No.LQ20F050005)。
文摘The heterojunction integration of two-dimensional(2D)materials via van der Waals(vdW)forces,unencumbered by lattice and processing constraints,constitutes an efficacious approach to enhance the overall optoelectronic performance of photodetectors,due to an assortment of distinctive light-matter interactions.Nonetheless,vdW heterojunction photodetectors based on transition metal dichalcogenides(TMDs)face an inevitable trade-off between low dark currents and high responsivity,curtailing the application potential of myriad novel optoelectronic components in sensing,spectral,and communication systems.In this study,we present the successful actualization of a highly sensitive,self-powered,and gate-tunable bipolar response photodetector.The mechanisms underlying photocurrent generation were scrutinized via bias-,power-,and position-dependent mapping photoresponse measurements,identifying the photovoltaic effect,which is attributable to the Schottky junction’s built-in electric field,as the predominant mechanism.The prototype Au-WS2-graphene photodetector exhibits a remarkable light on/off ratio of 1.2×10^(6),a specific detectivity of 6.12×10^(11)cm H^(z1/2)W^(-1)with 20μs response time at 638 nm.The wide gate-tunable responsivity provides an adjustability scope,ranging from 0.9 to 3.1 A W^(-1).Notably,the device demonstrates an exceptional linear photocurrent response,with a linear dynamic range(LDR)value approximating 130 dB,which significantly surpasses that of other photodetectors based on TMDs.
