本文提出了一种石墨烯场效应晶体管(Graphene Field Effect Transistors,GFET)的小信号等效电路模型,该模型考虑了金属-石墨烯界面的内部物理传输现象,即漏极与源极的接触电阻.提出了一种将接触电阻从等效电路中本征和寄生部分分离的方...本文提出了一种石墨烯场效应晶体管(Graphene Field Effect Transistors,GFET)的小信号等效电路模型,该模型考虑了金属-石墨烯界面的内部物理传输现象,即漏极与源极的接触电阻.提出了一种将接触电阻从等效电路中本征和寄生部分分离的方法,接触电阻有效且准确的分离能够模拟其对该器件截止频率fT和最大振荡频率fmax的影响.基于所建立的小信号等效电路,提出了GFET的高频等效噪声电路模型.噪声模型包括散粒噪声、热通道噪声和热噪声,基于这些噪声模型,在500 MHz~30 GHz的频率范围内通过噪声去嵌提取出本征噪声相关矩阵,利用其中的最小噪声系数(NFmin)得到接触电阻以及不同噪声源对高频噪声的影响.最终通过模拟数据与实测数据的验证分析,所提模型能够有效且准确的表征该器件的小信号特性以及高频噪声特性,并且接触电阻的影响不可忽略.展开更多
A simple,convenient,and highly sensitive bio-interface for graphene field-effect transistors(GFETs) based on multifunctional nano-denatured bovine serum albumin(nano-dBSA) functionalization was developed to target can...A simple,convenient,and highly sensitive bio-interface for graphene field-effect transistors(GFETs) based on multifunctional nano-denatured bovine serum albumin(nano-dBSA) functionalization was developed to target cancer bio-markers.The novel graphene–protein bioelectronic interface was constructed by heating to denature native BSA on the graphene substrate surface.The formed nano-d BSA film served as the cross-linker to immobilize monoclonal antibody against car-cinoembryonic antigen(anti-CEA mAb) on the graphene channel activated by EDC and Sulfo-NHS.The nano-dBSA film worked as a self-protecting layer of graphene to prevent surface contamination by lithographic processing.The improved GFETbiosensor exhibited good specificity and high sensitivity toward the target at an ultralow concentration of 337.58 fg mL-1.The electrical detection of the binding of CEA followed the Hill model for ligand–receptor interaction,indicating the negative binding cooperativity between CEA and anti-CEA mAb with a dissociation constant of 6.82×10-10M.The multifunctional nano-dBSA functionalization can confer a new function to graphene-like 2D nanomaterials and provide a promising bio-functionalization method for clinical application in biosensing,nanomedicine,and drug delivery.展开更多
Graphene field-effect transistors(GFET) have attracted much attention in the radio frequency(RF) and microwave fields because of its extremely high carrier mobility. In this paper, a GFET with a gate length of 5 μm i...Graphene field-effect transistors(GFET) have attracted much attention in the radio frequency(RF) and microwave fields because of its extremely high carrier mobility. In this paper, a GFET with a gate length of 5 μm is fabricated through the van der Walls(vdW) transfer process, and then the existing large-signal GFET model is described, and the model is implemented in Verilog-A for analysis in RF and microwave circuits. Next a double-balanced mixer based on four GFETs is designed and analyzed in advanced design system(ADS) tools. Finally, the simulation results show that with the input of 300 and 280 MHz,the IIP3 of the mixed signal is 24.5 dBm.展开更多
基金the support of grants from the National Key R&D Program of China(Nos.2018YFA0108202 and 2017YFA0205300)the National Natural Science Foundation of China(Nos.61571429,61801464,61801465,and 81471748)+1 种基金the STS Project of the Chinese Academy of Sciences(NO.KFJ-STS-SCYD-120)the Science and Technology Commission of Shanghai Municipality(Nos.16410711800 and 14391901900)
文摘A simple,convenient,and highly sensitive bio-interface for graphene field-effect transistors(GFETs) based on multifunctional nano-denatured bovine serum albumin(nano-dBSA) functionalization was developed to target cancer bio-markers.The novel graphene–protein bioelectronic interface was constructed by heating to denature native BSA on the graphene substrate surface.The formed nano-d BSA film served as the cross-linker to immobilize monoclonal antibody against car-cinoembryonic antigen(anti-CEA mAb) on the graphene channel activated by EDC and Sulfo-NHS.The nano-dBSA film worked as a self-protecting layer of graphene to prevent surface contamination by lithographic processing.The improved GFETbiosensor exhibited good specificity and high sensitivity toward the target at an ultralow concentration of 337.58 fg mL-1.The electrical detection of the binding of CEA followed the Hill model for ligand–receptor interaction,indicating the negative binding cooperativity between CEA and anti-CEA mAb with a dissociation constant of 6.82×10-10M.The multifunctional nano-dBSA functionalization can confer a new function to graphene-like 2D nanomaterials and provide a promising bio-functionalization method for clinical application in biosensing,nanomedicine,and drug delivery.
基金National Natural Science Foundation of China(Grant Nos.51925208,61974157,61851401,62122082)Key Research Project of Frontier Science,Chinese Academy of Sciences(QYZDB-SSW-JSC021)+3 种基金Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB30030000)National Science and Technology Major Project(2016ZX02301003)Science and Technology Innovation Action Plan of Shanghai Science and Technology Committee(20501130700)Science and Technology Commission of Shanghai Municipality(19JC1415500)。
文摘Graphene field-effect transistors(GFET) have attracted much attention in the radio frequency(RF) and microwave fields because of its extremely high carrier mobility. In this paper, a GFET with a gate length of 5 μm is fabricated through the van der Walls(vdW) transfer process, and then the existing large-signal GFET model is described, and the model is implemented in Verilog-A for analysis in RF and microwave circuits. Next a double-balanced mixer based on four GFETs is designed and analyzed in advanced design system(ADS) tools. Finally, the simulation results show that with the input of 300 and 280 MHz,the IIP3 of the mixed signal is 24.5 dBm.
