The ability to visualise transparent objects such as live cells is central to understanding biological processes.Here we experime ntally demonstrate a novel nano structured coverslip that converts phase information to...The ability to visualise transparent objects such as live cells is central to understanding biological processes.Here we experime ntally demonstrate a novel nano structured coverslip that converts phase information to high-contrast intensity images.This compact device enables real-time,all-optical gen eration of pseudo three-dime nsion al images of phase objects on transmission.We show that by placing unstained human cancer cells on the device,the internal structure within the cells can be clearly seen.Our research demonstrates the significant potential of nanophotonic devices for integration into compact imaging and medical diagnostic devices.展开更多
Atomically thin MoS2 films have attracted significant attention due to excellent electrical and optical properties.The development of device applications demands the production of large-area thin film which is still a...Atomically thin MoS2 films have attracted significant attention due to excellent electrical and optical properties.The development of device applications demands the production of large-area thin film which is still an obstacle.In this work we developed a facile method to directly grow large-area MoS2 thin film on Si O2 substrate via ambient pressure chemical vapor deposition method. The characterizations by spectroscopy and electron microscopy reveal that the as-grown MoS2 film is mainly bilayer and trilayer with high quality. Back-gate field-effect transistor based on such MoS2 thin film shows carrier mobility up to 3.4 cm2V-1s-1 and on/off ratio of 105. The large-area atomically thin MoS2 prepared in this work has the potential for wide optoelectronic and photonic device applications.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
基金the Australian Research Council Discovery Projects Scheme(DP 160100983,DPI80101387)the Center of Excelle nee Scheme(CE200100010)the National Health and Medical Research Council Career Development Fellowship(APP1124762)。
文摘The ability to visualise transparent objects such as live cells is central to understanding biological processes.Here we experime ntally demonstrate a novel nano structured coverslip that converts phase information to high-contrast intensity images.This compact device enables real-time,all-optical gen eration of pseudo three-dime nsion al images of phase objects on transmission.We show that by placing unstained human cancer cells on the device,the internal structure within the cells can be clearly seen.Our research demonstrates the significant potential of nanophotonic devices for integration into compact imaging and medical diagnostic devices.
基金the National High Technology Research and Development Program of China (863 Program) (Grant No.2013AA031903)the Youth 973 Program (Grant No.2015CB932700)+7 种基金the National Natural Science Foundation of China (Grant Nos.91433107, 51222208, and 51290273)the Doctoral Fund of Ministry of Education of China (Grant No.20123201120026)ARC DP (DP140101501)ARC DECRA (DE120101569)Victoria DSI top-up grantthe Natural Science Foundation of Jiangsu Province (No.BK20130328)China Postdoctoral Science Foundation (No. 2014M551654)Jiangsu Province Postdoctoral Science Foundation (No.1301020A)
文摘Atomically thin MoS2 films have attracted significant attention due to excellent electrical and optical properties.The development of device applications demands the production of large-area thin film which is still an obstacle.In this work we developed a facile method to directly grow large-area MoS2 thin film on Si O2 substrate via ambient pressure chemical vapor deposition method. The characterizations by spectroscopy and electron microscopy reveal that the as-grown MoS2 film is mainly bilayer and trilayer with high quality. Back-gate field-effect transistor based on such MoS2 thin film shows carrier mobility up to 3.4 cm2V-1s-1 and on/off ratio of 105. The large-area atomically thin MoS2 prepared in this work has the potential for wide optoelectronic and photonic device applications.
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.
