Metal-semiconductor diodes constructed from two-dimensional(2D)van der Waals heterostructures show excellent gate electrostatics and a large built-in electric field at the tunnel junction,which can be exploited to mak...Metal-semiconductor diodes constructed from two-dimensional(2D)van der Waals heterostructures show excellent gate electrostatics and a large built-in electric field at the tunnel junction,which can be exploited to make highly sensitive photodetector.Here we demonstrate a metal-semiconductor photodiode constructed by the monolayer graphene(Gr)on a few-layer black phosphorus(BP).Due to the presence of a built-in potential barrier(~0.09±0.03 eV)at the Gr-BP interface,the photoresponsivity of the Gr-BP device is enhanced by a factor of 672%,and the external quantum efficiency(EQE)increases to648%from 84%of the bare BP.Electrostatic gating allows the BP channel to be switched between p-type and n-type conduction.We further demonstrate that excitation laser power can be used to control the current polarity of the Gr-BP device due to photon-induced doping.The versatility of the Gr-BP junctions in terms of electrostatic bias-induced or light-induced switching of current polarity is potentially useful for making dynamically reconfigurable digital circuits.展开更多
The successful applications of two-dimensional(2 D)transition metal dichalcogenides highly rely on rational regulation of their electronic properties.The nondestructive and controllable doping strategy is of great imp...The successful applications of two-dimensional(2 D)transition metal dichalcogenides highly rely on rational regulation of their electronic properties.The nondestructive and controllable doping strategy is of great importance to implement 2 D materials in electronic devices.Herein,we propose a straightforward and effective method to realize controllable n-type doping in WSe_(2)monolayer by electron beam irradiation.Electrical measurements and photoluminescence(PL)spectra verify the strong n-doping in electron beam-treated WSe_(2)monolayers.The n-type doping arises from the generation of Se vacancies and the doping degree is precisely controlled by irradiation fluences.Due to the n-dopinginduced narrowing of the Schottky barrier,the current of back-gated monolayer WSe_(2)is enhanced by an order of magnitude and a$8?increase in the electron filed-effect mobility is observed.Remarkably,it is a moderate method without significant reduction in electrical performance and severe damage to lattice structures even under ultra-high doses of irradiation.展开更多
基金the financial support provided by the Fundamental Research Funds for the Central Universities(Nos.NS2020008,NC2018001,NJ2020003,NZ2020001)the Program for Innovative Talents and Entrepreneur in Jiangsu,Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Nos.MCMS-I-0419G02,MCMS-I-0421K01)+2 种基金National Key Research and Development Program of China(No.2019YFA0705400)Australian Research Council Future Fellowship(No.FT160100205)DECRA Fellowship(No.DE200101622)。
文摘Metal-semiconductor diodes constructed from two-dimensional(2D)van der Waals heterostructures show excellent gate electrostatics and a large built-in electric field at the tunnel junction,which can be exploited to make highly sensitive photodetector.Here we demonstrate a metal-semiconductor photodiode constructed by the monolayer graphene(Gr)on a few-layer black phosphorus(BP).Due to the presence of a built-in potential barrier(~0.09±0.03 eV)at the Gr-BP interface,the photoresponsivity of the Gr-BP device is enhanced by a factor of 672%,and the external quantum efficiency(EQE)increases to648%from 84%of the bare BP.Electrostatic gating allows the BP channel to be switched between p-type and n-type conduction.We further demonstrate that excitation laser power can be used to control the current polarity of the Gr-BP device due to photon-induced doping.The versatility of the Gr-BP junctions in terms of electrostatic bias-induced or light-induced switching of current polarity is potentially useful for making dynamically reconfigurable digital circuits.
基金supported by the KRDPC(No.2019YFA0308000)National Natural Science Foundation of China(Nos.61927808and 91963130)。
文摘The successful applications of two-dimensional(2 D)transition metal dichalcogenides highly rely on rational regulation of their electronic properties.The nondestructive and controllable doping strategy is of great importance to implement 2 D materials in electronic devices.Herein,we propose a straightforward and effective method to realize controllable n-type doping in WSe_(2)monolayer by electron beam irradiation.Electrical measurements and photoluminescence(PL)spectra verify the strong n-doping in electron beam-treated WSe_(2)monolayers.The n-type doping arises from the generation of Se vacancies and the doping degree is precisely controlled by irradiation fluences.Due to the n-dopinginduced narrowing of the Schottky barrier,the current of back-gated monolayer WSe_(2)is enhanced by an order of magnitude and a$8?increase in the electron filed-effect mobility is observed.Remarkably,it is a moderate method without significant reduction in electrical performance and severe damage to lattice structures even under ultra-high doses of irradiation.
