High-performance infrared(IR)photodetectors made by low dimensional materials promise a wide range of applications in communication,security and biomedicine.Moreover,light-harvesting effects based on novel plasmonic m...High-performance infrared(IR)photodetectors made by low dimensional materials promise a wide range of applications in communication,security and biomedicine.Moreover,light-harvesting effects based on novel plasmonic materials and their combinations with two-dimensional(2 D)materials have raised tremendous interest in recent years,as they may potentially help the device complement or surpass currently commercialized IR photodetectors.Graphene is a particularly attractive plasmonic material because graphene plasmons are electrically tunable with a high degree of electromagnetic confinement in the mid-infrared(mid-IR)to terahertz regime and the field concentration can be further enhanced by forming nanostructures.Here,we report an efficient mid-IR room-temperature photodetector enhanced by plasmonic effect in graphene nanoresonators(GNRs)/graphene heterostructure.The plasmon polaritons in GNRs are size-dependent with strong field localization.Considering that the size and density of GNRs are controllable by chemical vapor deposition method,our work opens a cost-effective and scalable pathway to fabricate efficient IR optoelectronic devices with wavelength tunability.展开更多
The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneiti...The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneities in the phase,structure and composition of these functional materials makes it difficult to directly monitor and identify the influence of local physicochemical parameters on their global functionality.In this review we will discuss recent developments in the field of IR nanospectroscopy that enables the extraction of detailed chemical information at the nanoscale and the identification of nanoscale properties that influence the global performances of functional materials.Specifically,we will discuss the ways by which infrared (IR) nanospectroscopy techniques,namely photo thermal induced resonance (PTIR) and scattering scanning near-field optical microscopy (s-SNOM),are utilized in order to identify nanoscale properties and their influence on the functionality of halide-perovskite solar cells and catalytic nanoparticles.In the last part of this review we will address the technical challenges and opportunities in expanding the scope of IR nanospectroscopy measurements into the field of electrochemistry-based functional materials.展开更多
We used scattering-type scanning near-field optical microscopy(s-SNOM)to investigate the plasmonic properties of edges in well-defined graphene nanostructures,including sharp tapers,nanoribbons and nanogaps,which were...We used scattering-type scanning near-field optical microscopy(s-SNOM)to investigate the plasmonic properties of edges in well-defined graphene nanostructures,including sharp tapers,nanoribbons and nanogaps,which were all fabricated via the growth-etching chemical vapor deposition(GECVD)method.The obtained near-field images revealed the localized plasmon modes along the graphene nanoribbon;these modes strongly depended on the size of the graphene pattern,the angle of the tapered graphene and the infrared excitation wavelength.These interesting plasmon modes were verified by numerical simulations and explained by the reflection,and interference of electromagnetic waves at the graphene–SiO_(2) edge.The constructive interference at the graphene nanogap caused by charge accumulation was demonstrated for the first time.Using the infrared nanoimaging technique,greater plasmon broadening was observed in the zigzag edge than in the armchair edge.Our study suggests that graphene edges should be separated by an effective working distance to avoid the overlapping of localized plasmon modes,which is very important for the design of graphene-based plasmonic circuits and devices.展开更多
Mesoporous silica nanoparticles(MSNPs)are promising nanomedicine vehicles due to their biocompatibility and ability to carry large cargoes.It is critical in nanomedicine development to be able to map their uptake in c...Mesoporous silica nanoparticles(MSNPs)are promising nanomedicine vehicles due to their biocompatibility and ability to carry large cargoes.It is critical in nanomedicine development to be able to map their uptake in cells,including distinguishing surface associated MSNPs from those that are embedded or internalized into cells.Conventional nanoscale imaging techniques,such as electron and fluorescence microscopies,however,generally require the use of stains and labels to image both the biological material and the nanomedicines,which can interfere with the biological processes at play.We demonstrate an alternative imaging technique for investigating the interactions between cells and nanostructures,scatteringtype scanning near-field optical microscopy(s-SNOM).s-SNOM combines the chemical sensitivity of infrared spectroscopy with the nanoscale spatial resolving power of scanning probe microscopy.We use the technique to chemically map the uptake of MSNPs in whole human glioblastoma cells and show that the simultaneously acquired topographical information can provide the embedding status of the MSNPs.We focus our imaging efforts on the lamellipodia and filopodia structures at the peripheries of the cells due to their significance in cancer invasiveness.展开更多
基金support from the National Key Research&Development Program(No.2016YFA0201902,2018YFA0703200)Shenzhen Nanshan District Pilotage Team Program(LHTD20170006)+4 种基金National Natural Science Foundation of China(61974099 and 61604102,51773041,61890940)Shanghai Committee of Science and Technology in China(18ZR1404900)Natural Science Research Project for Anhui Universities(Grant No.KJ2019A0596)Youth Project of Provincial Natural Science Foundation of Anhui(Grant No.2008085QF319)Australian Research Council(ARC,FT150100450 and IH150100006)。
文摘High-performance infrared(IR)photodetectors made by low dimensional materials promise a wide range of applications in communication,security and biomedicine.Moreover,light-harvesting effects based on novel plasmonic materials and their combinations with two-dimensional(2 D)materials have raised tremendous interest in recent years,as they may potentially help the device complement or surpass currently commercialized IR photodetectors.Graphene is a particularly attractive plasmonic material because graphene plasmons are electrically tunable with a high degree of electromagnetic confinement in the mid-infrared(mid-IR)to terahertz regime and the field concentration can be further enhanced by forming nanostructures.Here,we report an efficient mid-IR room-temperature photodetector enhanced by plasmonic effect in graphene nanoresonators(GNRs)/graphene heterostructure.The plasmon polaritons in GNRs are size-dependent with strong field localization.Considering that the size and density of GNRs are controllable by chemical vapor deposition method,our work opens a cost-effective and scalable pathway to fabricate efficient IR optoelectronic devices with wavelength tunability.
基金Supported by National Basic Research Program of China(2014CB 921102)National Natural Science Foundation of China(11434009,11374279,11461161009)+1 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB01020000)the Fundamental Research Funds for the Central Universities(WK2030020027)
文摘The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneities in the phase,structure and composition of these functional materials makes it difficult to directly monitor and identify the influence of local physicochemical parameters on their global functionality.In this review we will discuss recent developments in the field of IR nanospectroscopy that enables the extraction of detailed chemical information at the nanoscale and the identification of nanoscale properties that influence the global performances of functional materials.Specifically,we will discuss the ways by which infrared (IR) nanospectroscopy techniques,namely photo thermal induced resonance (PTIR) and scattering scanning near-field optical microscopy (s-SNOM),are utilized in order to identify nanoscale properties and their influence on the functionality of halide-perovskite solar cells and catalytic nanoparticles.In the last part of this review we will address the technical challenges and opportunities in expanding the scope of IR nanospectroscopy measurements into the field of electrochemistry-based functional materials.
基金support from the National Key Research&Development Program(2015CB932700 and 2016YFA0201902)the National Natural Science Foundation of China(grant No.51290273,91433107,51325205 and 51521091)+6 种基金the Doctoral Fund of the Ministry of Education of China(grant No.20123201120026)ARC(DP140101501 and FT150100450)the Collaborative Innovation Center of Suzhou Nano Science&Technologythe Priority Academic Program Development of Jiangsu Higher Education InstitutionsA*STAR Pharos Programme(grant No.1527000014,with Project No.R-263-000-B91-305)Competitive Research Program(CRP Award No.NRF-CRP15-2015-03)the National Research Foundation,Prime Minister’s Office,Singapore。
文摘We used scattering-type scanning near-field optical microscopy(s-SNOM)to investigate the plasmonic properties of edges in well-defined graphene nanostructures,including sharp tapers,nanoribbons and nanogaps,which were all fabricated via the growth-etching chemical vapor deposition(GECVD)method.The obtained near-field images revealed the localized plasmon modes along the graphene nanoribbon;these modes strongly depended on the size of the graphene pattern,the angle of the tapered graphene and the infrared excitation wavelength.These interesting plasmon modes were verified by numerical simulations and explained by the reflection,and interference of electromagnetic waves at the graphene–SiO_(2) edge.The constructive interference at the graphene nanogap caused by charge accumulation was demonstrated for the first time.Using the infrared nanoimaging technique,greater plasmon broadening was observed in the zigzag edge than in the armchair edge.Our study suggests that graphene edges should be separated by an effective working distance to avoid the overlapping of localized plasmon modes,which is very important for the design of graphene-based plasmonic circuits and devices.
基金support from EPSRC(EP/N509486/1,EP/R513052/1).J.M.T.acknowledges an EPSRC funded CDT in Neurotechnology for PhD fundingA.P acknowledges an Imperial College Research Fellowship for funding.C.C.P.acknowledges a Cancer Research UK grant(C68186/A28503).
文摘Mesoporous silica nanoparticles(MSNPs)are promising nanomedicine vehicles due to their biocompatibility and ability to carry large cargoes.It is critical in nanomedicine development to be able to map their uptake in cells,including distinguishing surface associated MSNPs from those that are embedded or internalized into cells.Conventional nanoscale imaging techniques,such as electron and fluorescence microscopies,however,generally require the use of stains and labels to image both the biological material and the nanomedicines,which can interfere with the biological processes at play.We demonstrate an alternative imaging technique for investigating the interactions between cells and nanostructures,scatteringtype scanning near-field optical microscopy(s-SNOM).s-SNOM combines the chemical sensitivity of infrared spectroscopy with the nanoscale spatial resolving power of scanning probe microscopy.We use the technique to chemically map the uptake of MSNPs in whole human glioblastoma cells and show that the simultaneously acquired topographical information can provide the embedding status of the MSNPs.We focus our imaging efforts on the lamellipodia and filopodia structures at the peripheries of the cells due to their significance in cancer invasiveness.
