The fundamental advantages of carbon-based graphene material,such as its high tunnelling probability,symmetric band structure(linear dependence of the energy band on the wave direction),low effective mass,and characte...The fundamental advantages of carbon-based graphene material,such as its high tunnelling probability,symmetric band structure(linear dependence of the energy band on the wave direction),low effective mass,and characteristics of its 2D atomic layers,are the main focus of this research work.The impact of channel thickness,gate under-lap,asymmetric source/drain doping method,workfunction of gate contact,and High-K material on Graphene-based Tunnel Field Effect Transistor(TFET)is analyzed with 20 nm technology.Physical modelling and electrical characteristic performance have been simulated using the Atlas device simulator of SILVACO TCAD with user-defined material syntax for the newly included graphene material in comparison to silicon carbide(SiC).The simulation results in significant suppression of ambipolar current to voltage characteristics of TFET and modelled device exhibits a significant improvement in subthreshold swing(0.0159 V/decade),the ratio of Ion/Ioff(1000),and threshold voltage(-0.2 V with highly doped p-type source and 0.2 V with highly doped n-type drain)with power supply of 0.5 V,which make it useful for low power digital applications.展开更多
Graphene has attracted enormous interests due to its unique physical, mechanical, and electrical properties. Specially, graphene-based field-effect transistors (FETs) have evolved rapidly and are now considered as a...Graphene has attracted enormous interests due to its unique physical, mechanical, and electrical properties. Specially, graphene-based field-effect transistors (FETs) have evolved rapidly and are now considered as an option for conventional silicon devices. As a critical step in the design cycle of modem IC products, compact model refers to the development of models for integrated semiconductor devices for use in circuit simulations. The purpose of this review is to provide a theoretical description of current compact model of graphene field-effect transistors. Special attention is devoted to the charge sheet model, drift-diffusion model, Boltzmann equation, density of states (DOS), and surface-potential-based compact model. Finally, an outlook of this field is briefly discussed.展开更多
The temperature-dependent effect of residual charge carrier (no), at the Dirac point, on mobility is studied. We fabricate and characterize a graphene field effect transistor (GFET) using 7nm TiO2 as the top-gate ...The temperature-dependent effect of residual charge carrier (no), at the Dirac point, on mobility is studied. We fabricate and characterize a graphene field effect transistor (GFET) using 7nm TiO2 as the top-gate dielectric. The temperature-dependent gate voltage-drain current and room temperature gate capacitance are measured to extract the carrier mobility and to estimate the quantum capacitance of the GFET. The device shows the mobility value of gOO cm^2 /V.s at room temperature and it decreases to 45 cm^2 /V.s for 20 K due to the increase of n0. These results indicate that the phonon scattering is not the dominant process for the unevenness dielectric layer while the coulomb scattering by charged impurities degrades the device characteristically at low temperature.展开更多
The tunneling current in a graphene nanoribbon tunnel field effect transistor(GNR-TFET) has been quantum mechanically modeled. The tunneling current in the GNR-TFET was compared based on calculations of the Dirac-like...The tunneling current in a graphene nanoribbon tunnel field effect transistor(GNR-TFET) has been quantum mechanically modeled. The tunneling current in the GNR-TFET was compared based on calculations of the Dirac-like equation and Schrodinger’s equation. To calculate the electron transmittance, a numerical approach-namely the transfer matrix method(TMM)-was employed and the Launder formula was used to compute the tunneling current. The results suggest that the tunneling currents that were calculated using both equations have similar characteristics for the same parameters, even though they have different values. The tunneling currents that were calculated by applying the Dirac-like equation were lower than those calculated using Schrodinger’s equation.展开更多
The luminescence intensity regulation of organic light-emitting transistor(OLED)device can be achieved effectively by the combination of graphene vertical field effect transistor(GVFET)and OLED.In this paper,we fabric...The luminescence intensity regulation of organic light-emitting transistor(OLED)device can be achieved effectively by the combination of graphene vertical field effect transistor(GVFET)and OLED.In this paper,we fabricate and characterize the graphene vertical field-effect transistor with gate dielectric of ion-gel film,confirming that its current switching ratio reaches up to 102.Because of the property of high light transmittance in ion-gel film,the OLED device prepared with graphene/PEDOT:PSS as composite anode exhibits good optical properties.We also prepare the graphene vertical organic light-emitting field effect transistor(GVOLEFET)by the combination of GVFET and graphene OLED,analyzing its electrical and optical properties,and confirming that the luminescence intensity can be significantly changed by regulating the gate voltage.展开更多
In this paper,high temperature direct current(DC) performance of bilayer epitaxial graphene device on SiC substrate is studied in a temperature range from 25℃ to 200℃.At a gate voltage of-8 V(far from Dirac point...In this paper,high temperature direct current(DC) performance of bilayer epitaxial graphene device on SiC substrate is studied in a temperature range from 25℃ to 200℃.At a gate voltage of-8 V(far from Dirac point),the drainsource current decreases obviously with increasing temperature,but it has little change at a gate bias of +8 V(near Dirac point).The competing interactions between scattering and thermal activation are responsible for the different reduction tendencies.Four different kinds of scatterings are taken into account to qualitatively analyze the carrier mobility under different temperatures.The devices exhibit almost unchanged DC performances after high temperature measurements at 200℃ for 5 hours in air ambience,demonstrating the high thermal stabilities of the bilayer epitaxial graphene devices.展开更多
We report the fabrication and characterization of a single-layer graphene field-effect terahertz detector, which is cou- pled with dipole-like antennas based on the self-mixing detector model. The graphene is grown by...We report the fabrication and characterization of a single-layer graphene field-effect terahertz detector, which is cou- pled with dipole-like antennas based on the self-mixing detector model. The graphene is grown by chemical vapor deposi- tion and then transferred onto an SiO2/Si substrate. We demonstrate room-temperature detection at 237 GHz. The detector could offer a voltage responsivity of 0.1 V/W and a noise equivalent power of 207 nW/Hz 1/2. Our modeling indicates that the observed photovoltage in the p-type gated channel can be well fit by the self-mixing theory. A different photoresponse other than self-mixing may apply for the n-type gated channel.展开更多
Field-effect transistors (FETs) for logic applications, graphene and MoS2, are discussed. These materials have based on two representative two-dimensional (2D) materials, drastically different properties and requi...Field-effect transistors (FETs) for logic applications, graphene and MoS2, are discussed. These materials have based on two representative two-dimensional (2D) materials, drastically different properties and require different consider- ations. The unique band structure of graphene necessitates engineering of the Dirac point, including the opening of the bandgap, the doping and the interface, before the graphene can be used in logic applications. On the other hand, MoS2 is a semiconductor, and its electron transport depends heavily on the surface properties, the number of layers, and the carrier density. Finally, we discuss the prospects for the future developments in 2D material transistors.展开更多
Adenosine triphosphate(ATP)is closely related to the pathogenesis of certain diseases,so the detection of trace ATP is of great significance to disease diagnosis and drug development.Graphene field-effect transistors(...Adenosine triphosphate(ATP)is closely related to the pathogenesis of certain diseases,so the detection of trace ATP is of great significance to disease diagnosis and drug development.Graphene field-effect transistors(GFETs)have been proven to be a promising platform for the rapid and accurate detection of small molecules,while the Debye shielding limits the sensitive detection in real samples.Here,a three-dimensional wrinkled graphene field-effect transistor(3D WG-FET)biosensor for ultra-sensitive detection of ATP is demonstrated.The lowest detection limit of 3D WG-FET for analyzing ATP is down to 3.01 aM,which is much lower than the reported results.In addition,the 3D WG-FET biosensor shows a good linear electrical response to ATP concentrations in a broad range of detection from 10 aM to 10 pM.Meanwhile,we achieved ultra-sensitive(LOD:10 aM)and quantitative(range from 10 aM to 100 fM)measurements of ATP in human serum.The 3D WG-FET also exhibits high specificity.This work may provide a novel approach to improve the sensitivity for the detection of ATP in complex biological matrix,showing a broad application value for early clinical diagnosis and food health monitoring.展开更多
Reduced graphene oxide (RGO) has the advantage of an aqueous and industrial-scale production route. No other approaches can rival the RGO field effect transistor platform in terms of cost (〈US$1) and portability ...Reduced graphene oxide (RGO) has the advantage of an aqueous and industrial-scale production route. No other approaches can rival the RGO field effect transistor platform in terms of cost (〈US$1) and portability (millimetre scale). However the large deviations in the electrical resistivity of this fabricated material prevent it from being used widely. After an ethanol chemical vapor deposition (CVD) post-treatment to graphene oxide with ethanol, carbon islets are deposited preferentially at the edges of existing flakes. With a 2-h treatment, the standard deviation in electrical resistance of the treated chips can be reduced by 99.95%. Thus this process could enable RGO to be used in practical electronic devices.展开更多
Reducing the contact resistance without degrading the mobility property is crucial to achieve high-performance graphene field effect transistors. Also, the idea of modifying the graphene surface by etching away the de...Reducing the contact resistance without degrading the mobility property is crucial to achieve high-performance graphene field effect transistors. Also, the idea of modifying the graphene surface by etching away the deposited metal provides a new angle to achieve this goal. We exploit this idea by providing a new process method which reduces the contact resistance from 597Ω ·μm to sub 200 Ω ·μm while no degradation of mobility is observed in the devices. This simple process method avoids the drawbacks of uncontrollability, ineffectiveness, and trade-off with mobility which often exist in the previously proposed methods.展开更多
Effective detection of methamphetamine(Met)requires a fast,sensitive,and cheap testing assay.However,commercially available methods require expensive instruments and highly trained operators,which are time-consuming a...Effective detection of methamphetamine(Met)requires a fast,sensitive,and cheap testing assay.However,commercially available methods require expensive instruments and highly trained operators,which are time-consuming and labor-intensive.Herein,an antibody-modified graphene transistor assay is developed for sensitive and minute-level detection of Met in complex environments.The anti-Met probe captured charged targets within 120 s,leading to a p-doping effect near the graphene channel.The limit of detection reaches 50 aM(5.0×10^(-17)M)Met in solution.The graphene transistor would be a valuable tool for Met detection effective prevention of drug abuse.展开更多
Nitrogen doping is a promising way to modulate the electrical properties of graphene to realize graphene-based electronics and promise fascinating properties and applications.Herein,we report a method to noncovalently...Nitrogen doping is a promising way to modulate the electrical properties of graphene to realize graphene-based electronics and promise fascinating properties and applications.Herein,we report a method to noncovalently assembly titanium(Ⅳ) bis(ammoniumlactato) dihydroxide(Ti complex) on nitrogen-doped graphene to create a reliable hybrids which can be used as a reversible chemical induced switching.As the adsorption and desorption of Ti complex in sequential treatments,the conductance of the nitrogen-doped graphene transistors was finely modulated.Control experiments with pristine graphene clearly demonstrated the important effort of the nitrogen in this chemical sensor.Under optimized conditions,nitrogen-doped graphene transistors open up new ways to develop multifunctional devices with high sensitivity.展开更多
In this work, we report a broadband terahertz wave modulator based on a top-gate graphene field effect tran- sistor with polyimide as the gate dielectric on a PET substrate. The transmission of the terahertz wave is m...In this work, we report a broadband terahertz wave modulator based on a top-gate graphene field effect tran- sistor with polyimide as the gate dielectric on a PET substrate. The transmission of the terahertz wave is modulated by controlling the Fermi level of graphene via the polyimide as the top-gate dielectric material instead of the traditional dielectric materials. It is found that the terahertz modulator can achieve a modulation depth of ~20.9% with a small operating gate voltage of 3.5 V and a low insertion loss of 2.1 dB.展开更多
本文针对不同结构、尺寸的石墨烯场效应晶体管(graphene field effect transistors,GFET)开展了基于10 keV-X射线的总剂量效应研究.结果表明,随累积剂量的增大,不同结构GFET的狄拉克电压V_(Dirac)和载流子迁移率μ不断退化;相比于背栅型...本文针对不同结构、尺寸的石墨烯场效应晶体管(graphene field effect transistors,GFET)开展了基于10 keV-X射线的总剂量效应研究.结果表明,随累积剂量的增大,不同结构GFET的狄拉克电压V_(Dirac)和载流子迁移率μ不断退化;相比于背栅型GFET,顶栅型GFET的辐射损伤更加严重;尺寸对GFET器件的总剂量效应决定于器件结构;200μm×200μm尺寸的顶栅型GFET损伤最严重,而背栅型GFET是50μm×50μm尺寸的器件损伤最严重.研究表明:对于顶栅型GFET,辐照过程中在栅氧层中形成的氧化物陷阱电荷的积累是V_(Dirac)和μ降低的主要原因.背栅型GFET不仅受到辐射在栅氧化层中产生的陷阱电荷的影响,还受到石墨烯表面的氧吸附的影响.在此基础上,结合TCAD仿真工具实现了顶栅器件氧化层中辐射产生的氧化物陷阱电荷对器件辐射响应规律的仿真.相关研究结果对于石墨烯器件的抗辐照加固研究具有重大意义.展开更多
文摘The fundamental advantages of carbon-based graphene material,such as its high tunnelling probability,symmetric band structure(linear dependence of the energy band on the wave direction),low effective mass,and characteristics of its 2D atomic layers,are the main focus of this research work.The impact of channel thickness,gate under-lap,asymmetric source/drain doping method,workfunction of gate contact,and High-K material on Graphene-based Tunnel Field Effect Transistor(TFET)is analyzed with 20 nm technology.Physical modelling and electrical characteristic performance have been simulated using the Atlas device simulator of SILVACO TCAD with user-defined material syntax for the newly included graphene material in comparison to silicon carbide(SiC).The simulation results in significant suppression of ambipolar current to voltage characteristics of TFET and modelled device exhibits a significant improvement in subthreshold swing(0.0159 V/decade),the ratio of Ion/Ioff(1000),and threshold voltage(-0.2 V with highly doped p-type source and 0.2 V with highly doped n-type drain)with power supply of 0.5 V,which make it useful for low power digital applications.
基金Project supported by the Opening Project of Key Laboratory of Microelectronics Devices and Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences,the National Natural Science Foundation of China(Grant No.61574166)the National Basic Research Program of China(Grant No.2013CBA01604)+1 种基金the National Key Research and Development Program of China(Grant No.2016YFA0201802)and the Beijing Training Project for the Leading Talents in S&T,China(Grant No.Z151100000315008)
文摘Graphene has attracted enormous interests due to its unique physical, mechanical, and electrical properties. Specially, graphene-based field-effect transistors (FETs) have evolved rapidly and are now considered as an option for conventional silicon devices. As a critical step in the design cycle of modem IC products, compact model refers to the development of models for integrated semiconductor devices for use in circuit simulations. The purpose of this review is to provide a theoretical description of current compact model of graphene field-effect transistors. Special attention is devoted to the charge sheet model, drift-diffusion model, Boltzmann equation, density of states (DOS), and surface-potential-based compact model. Finally, an outlook of this field is briefly discussed.
文摘The temperature-dependent effect of residual charge carrier (no), at the Dirac point, on mobility is studied. We fabricate and characterize a graphene field effect transistor (GFET) using 7nm TiO2 as the top-gate dielectric. The temperature-dependent gate voltage-drain current and room temperature gate capacitance are measured to extract the carrier mobility and to estimate the quantum capacitance of the GFET. The device shows the mobility value of gOO cm^2 /V.s at room temperature and it decreases to 45 cm^2 /V.s for 20 K due to the increase of n0. These results indicate that the phonon scattering is not the dominant process for the unevenness dielectric layer while the coulomb scattering by charged impurities degrades the device characteristically at low temperature.
基金supported by Hibah Penelitian Berbasi Kompetensi 2018 RISTEKDIKTI Republic of Indonesia
文摘The tunneling current in a graphene nanoribbon tunnel field effect transistor(GNR-TFET) has been quantum mechanically modeled. The tunneling current in the GNR-TFET was compared based on calculations of the Dirac-like equation and Schrodinger’s equation. To calculate the electron transmittance, a numerical approach-namely the transfer matrix method(TMM)-was employed and the Launder formula was used to compute the tunneling current. The results suggest that the tunneling currents that were calculated using both equations have similar characteristics for the same parameters, even though they have different values. The tunneling currents that were calculated by applying the Dirac-like equation were lower than those calculated using Schrodinger’s equation.
基金Project supported by the National Natural Science Foundation of China(Grant No.31872901)the National Key Research and Development Program of China(Grant No.2016YFA0501602).
文摘The luminescence intensity regulation of organic light-emitting transistor(OLED)device can be achieved effectively by the combination of graphene vertical field effect transistor(GVFET)and OLED.In this paper,we fabricate and characterize the graphene vertical field-effect transistor with gate dielectric of ion-gel film,confirming that its current switching ratio reaches up to 102.Because of the property of high light transmittance in ion-gel film,the OLED device prepared with graphene/PEDOT:PSS as composite anode exhibits good optical properties.We also prepare the graphene vertical organic light-emitting field effect transistor(GVOLEFET)by the combination of GVFET and graphene OLED,analyzing its electrical and optical properties,and confirming that the luminescence intensity can be significantly changed by regulating the gate voltage.
基金Project supported by the National Natural Science Foundation of China(Grant No.61306006)
文摘In this paper,high temperature direct current(DC) performance of bilayer epitaxial graphene device on SiC substrate is studied in a temperature range from 25℃ to 200℃.At a gate voltage of-8 V(far from Dirac point),the drainsource current decreases obviously with increasing temperature,but it has little change at a gate bias of +8 V(near Dirac point).The competing interactions between scattering and thermal activation are responsible for the different reduction tendencies.Four different kinds of scatterings are taken into account to qualitatively analyze the carrier mobility under different temperatures.The devices exhibit almost unchanged DC performances after high temperature measurements at 200℃ for 5 hours in air ambience,demonstrating the high thermal stabilities of the bilayer epitaxial graphene devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61271157,61401456,and 11403084)Jiangsu Provincial Planned Projects for Postdoctoral Research Funds(Grant No.1301054B)+4 种基金the Fund from Suzhou Industry Technology Bureau(Grant No.ZXG2012024)China Postdoctoral Science Foundation(Grant No.2014M551678)the Graduate Student Innovation Program for Universities of Jiangsu Province(Grant No.CXLX12-0724)the Fundamental Research Funds for the Central Universities(Grant No.JUDCF 12032)the Fund from National University of Defense Technology(Grant No.JC13-02-14)
文摘We report the fabrication and characterization of a single-layer graphene field-effect terahertz detector, which is cou- pled with dipole-like antennas based on the self-mixing detector model. The graphene is grown by chemical vapor deposi- tion and then transferred onto an SiO2/Si substrate. We demonstrate room-temperature detection at 237 GHz. The detector could offer a voltage responsivity of 0.1 V/W and a noise equivalent power of 207 nW/Hz 1/2. Our modeling indicates that the observed photovoltage in the p-type gated channel can be well fit by the self-mixing theory. A different photoresponse other than self-mixing may apply for the n-type gated channel.
基金supported by the National Basic Research Program of China (Grant No. 2013CBA01600)the National Natural Science Foundation of China (Grant Nos. 61261160499 and 11274154)+2 种基金the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2011ZX02707)the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2012302)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120091110028)
文摘Field-effect transistors (FETs) for logic applications, graphene and MoS2, are discussed. These materials have based on two representative two-dimensional (2D) materials, drastically different properties and require different consider- ations. The unique band structure of graphene necessitates engineering of the Dirac point, including the opening of the bandgap, the doping and the interface, before the graphene can be used in logic applications. On the other hand, MoS2 is a semiconductor, and its electron transport depends heavily on the surface properties, the number of layers, and the carrier density. Finally, we discuss the prospects for the future developments in 2D material transistors.
基金support from the National Natural Science Foundation of China(Nos.12274058 and 12104085)Taishan Scholars Program of Shandong Province(No.tsqn201812104)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2021QA008)the Qingchuang Science and Technology Plan of Shandong Province(No.2019KJJ017)the project of the Talent Introduction of Dezhou University(No.2021xjrc101).
文摘Adenosine triphosphate(ATP)is closely related to the pathogenesis of certain diseases,so the detection of trace ATP is of great significance to disease diagnosis and drug development.Graphene field-effect transistors(GFETs)have been proven to be a promising platform for the rapid and accurate detection of small molecules,while the Debye shielding limits the sensitive detection in real samples.Here,a three-dimensional wrinkled graphene field-effect transistor(3D WG-FET)biosensor for ultra-sensitive detection of ATP is demonstrated.The lowest detection limit of 3D WG-FET for analyzing ATP is down to 3.01 aM,which is much lower than the reported results.In addition,the 3D WG-FET biosensor shows a good linear electrical response to ATP concentrations in a broad range of detection from 10 aM to 10 pM.Meanwhile,we achieved ultra-sensitive(LOD:10 aM)and quantitative(range from 10 aM to 100 fM)measurements of ATP in human serum.The 3D WG-FET also exhibits high specificity.This work may provide a novel approach to improve the sensitivity for the detection of ATP in complex biological matrix,showing a broad application value for early clinical diagnosis and food health monitoring.
基金Project supported by the Institute for Sports Research(ISR)of Nanyang Technological University(NTU),the National Institute for Health Research(NIHR)Diet,Lifestyle&Physical Activity Biomedical Research Unit based at University Hospitals of Leicester and Loughborough University,and the International Graduate School Bio-Nano-Techa Joint Ph D Program of University of Natural Resources and Life Sciences Vienna(BOKU),the Austrian Institute of Technology(AIT)and NTU
文摘Reduced graphene oxide (RGO) has the advantage of an aqueous and industrial-scale production route. No other approaches can rival the RGO field effect transistor platform in terms of cost (〈US$1) and portability (millimetre scale). However the large deviations in the electrical resistivity of this fabricated material prevent it from being used widely. After an ethanol chemical vapor deposition (CVD) post-treatment to graphene oxide with ethanol, carbon islets are deposited preferentially at the edges of existing flakes. With a 2-h treatment, the standard deviation in electrical resistance of the treated chips can be reduced by 99.95%. Thus this process could enable RGO to be used in practical electronic devices.
基金Project by the National Science and Technology Major Project,China(Grant No.2011ZX02707.3)the National Natural Science Foundation of China(Grant No.61136005)+1 种基金the Chinese Academy of Sciences(Grant No.KGZD-EW-303)the Project of Beijing Municipal Science and Technology Commission,China(Grant No.Z151100003515003)
文摘Reducing the contact resistance without degrading the mobility property is crucial to achieve high-performance graphene field effect transistors. Also, the idea of modifying the graphene surface by etching away the deposited metal provides a new angle to achieve this goal. We exploit this idea by providing a new process method which reduces the contact resistance from 597Ω ·μm to sub 200 Ω ·μm while no degradation of mobility is observed in the devices. This simple process method avoids the drawbacks of uncontrollability, ineffectiveness, and trade-off with mobility which often exist in the previously proposed methods.
基金funded by the National Key R&D Program of China(No.2021YFE0201400)the National Natural Science Foundation of China(Nos.51773041,61890940,22066011)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB30000000)the Department of Education of Jiangxi Province(No.GJJ211105)Jiangxi Science&Technology Normal University(No.2021QNBJRC002)State Key Laboratory of Molecular Engineering of Polymers.
文摘Effective detection of methamphetamine(Met)requires a fast,sensitive,and cheap testing assay.However,commercially available methods require expensive instruments and highly trained operators,which are time-consuming and labor-intensive.Herein,an antibody-modified graphene transistor assay is developed for sensitive and minute-level detection of Met in complex environments.The anti-Met probe captured charged targets within 120 s,leading to a p-doping effect near the graphene channel.The limit of detection reaches 50 aM(5.0×10^(-17)M)Met in solution.The graphene transistor would be a valuable tool for Met detection effective prevention of drug abuse.
基金Financial support for this work was provided by the USA National Science Foundation (NSF) (Nos. CMMI- 0900509, CBET-0803142, and ECCS-0708998). Graphene oxide samples were supplied by Prof. Rodney S. Ruoff. The authors thank Dr. Heather A. Owen for technical support with SEM, and Dr. Leonidas E. Ocola for assistance in the electrode fabrication. The e-beam lithography was performed at the Center for Nanoscale Materials of Argonne National Laboratory, which is supported by the USA Department of Energy (No. DE- AC02-06CH11357). The SEM imaging was conducted at the Electron Microscope Laboratory of University of Wisconsin-Milwaukee.
文摘Nitrogen doping is a promising way to modulate the electrical properties of graphene to realize graphene-based electronics and promise fascinating properties and applications.Herein,we report a method to noncovalently assembly titanium(Ⅳ) bis(ammoniumlactato) dihydroxide(Ti complex) on nitrogen-doped graphene to create a reliable hybrids which can be used as a reversible chemical induced switching.As the adsorption and desorption of Ti complex in sequential treatments,the conductance of the nitrogen-doped graphene transistors was finely modulated.Control experiments with pristine graphene clearly demonstrated the important effort of the nitrogen in this chemical sensor.Under optimized conditions,nitrogen-doped graphene transistors open up new ways to develop multifunctional devices with high sensitivity.
基金supported by National Natural Science Foundation of China(Nos.51202022,51372033,61378028,and 61131005)the National High Technology Research and Development Program of China(No.2015AA034202)+6 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120185120011)the Fundamental Research Funds for the Central Universities(No.ZYGX2013Z001)the 111 Project(No.B13042)the Sichuan Youth Science and Technology Innovation Research Team Funding(No.2011JTD0006)the International Science and Technology Cooperation Program of China(No.2015DFR50870)the Key Grant Project of the Chinese Ministry of Education(No.313013)the Sino-German Cooperation PPP Program of China
文摘In this work, we report a broadband terahertz wave modulator based on a top-gate graphene field effect tran- sistor with polyimide as the gate dielectric on a PET substrate. The transmission of the terahertz wave is modulated by controlling the Fermi level of graphene via the polyimide as the top-gate dielectric material instead of the traditional dielectric materials. It is found that the terahertz modulator can achieve a modulation depth of ~20.9% with a small operating gate voltage of 3.5 V and a low insertion loss of 2.1 dB.
文摘本文针对不同结构、尺寸的石墨烯场效应晶体管(graphene field effect transistors,GFET)开展了基于10 keV-X射线的总剂量效应研究.结果表明,随累积剂量的增大,不同结构GFET的狄拉克电压V_(Dirac)和载流子迁移率μ不断退化;相比于背栅型GFET,顶栅型GFET的辐射损伤更加严重;尺寸对GFET器件的总剂量效应决定于器件结构;200μm×200μm尺寸的顶栅型GFET损伤最严重,而背栅型GFET是50μm×50μm尺寸的器件损伤最严重.研究表明:对于顶栅型GFET,辐照过程中在栅氧层中形成的氧化物陷阱电荷的积累是V_(Dirac)和μ降低的主要原因.背栅型GFET不仅受到辐射在栅氧化层中产生的陷阱电荷的影响,还受到石墨烯表面的氧吸附的影响.在此基础上,结合TCAD仿真工具实现了顶栅器件氧化层中辐射产生的氧化物陷阱电荷对器件辐射响应规律的仿真.相关研究结果对于石墨烯器件的抗辐照加固研究具有重大意义.
基金National Key R&D Program of China(2021YFB3601600)National Natural Science Foundation of China(61827813,52002368,62121005,62074147,62022081,61974099)+1 种基金Natural Science Foundation of Jilin Province(20230101345JC,20230101107JC,20230508132RC)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y201945,2019222)。
基金This work was supported by the Ministry of Sdence and Technology of China (Grant Nos. 2011CB933001 and 2011CB933002), National Natural Science Foundation of China (Grant Nos. 61322105, 61271051, 61321001, and 61390504), and Beijing Municipal Science and Technology Commission (Grant Nos. Z131100003213021 and D141100000614001).