Plasmonic materials and metamaterials have been widely utilized to achieve spectral transmission, reflection and absorption filters based on localized or delocalized resonances arising from the interaction of photons with nanoscale patterns. However, the realization of visible-frequency, high-performance, large-area, optical filters based on nanoplasmonic materials is rather challenging due to nanofabrication related problems (cost, fabrication imperfection, surface roughness) and optical losses of metals. Here, we propose and demonstrate large-area perfect absorbers and transmission color filters and photodectors that could overcome the difficulties associated with nanofabrication using a lithography-free approach. Our resonant flat optical design is based on a modified, asymmetric metal-insulator/semiconductor-metal (MI/SM) based Fabry-Perot cavity incorporated with plasmonic, lossy ultra-thin (~ 30 nm) Ag or (~ 5-15 nm) amorphous Si films. We demonstrated a narrow bandwidth (~17 nm) super absorber with 97% maximum absorption with a performance comparable to nanostructure/nanoparticle-based super absorbers. We also investigated transmission filters in which different colors can be obtained by controlling the spacer thickness of silicon dioxide or amorphous silicon. With measured performance of transmission peak intensity reaching 60% and a narrow-band of ~ 40 nm, our color filters exceed the performance of widely studied plasmonic nanohole array based color filters and make a good candidate for large-area narrow-band photodetection devices. Such plasmonic loss incorporated Fabry-Perot cavities using ultra-thin metallic or semiconductor films could suggest active and practical applications in spectrally selective optical (color and absorber) filters, optoelectronic devices with controlled bandwidth such as narrow-band photodetectors, and light-emitting devices.
{"title":"Large-area lithography-free perfect absorbers, color filters, and photodetectors at visible frequencies using ultra-thin silver or amorphous silicon films (Presentation Recording)","authors":"Zhongyang Li, S. Butun, Koray Aydin","doi":"10.1117/12.2187139","DOIUrl":"https://doi.org/10.1117/12.2187139","url":null,"abstract":"Plasmonic materials and metamaterials have been widely utilized to achieve spectral transmission, reflection and absorption filters based on localized or delocalized resonances arising from the interaction of photons with nanoscale patterns. However, the realization of visible-frequency, high-performance, large-area, optical filters based on nanoplasmonic materials is rather challenging due to nanofabrication related problems (cost, fabrication imperfection, surface roughness) and optical losses of metals. Here, we propose and demonstrate large-area perfect absorbers and transmission color filters and photodectors that could overcome the difficulties associated with nanofabrication using a lithography-free approach. Our resonant flat optical design is based on a modified, asymmetric metal-insulator/semiconductor-metal (MI/SM) based Fabry-Perot cavity incorporated with plasmonic, lossy ultra-thin (~ 30 nm) Ag or (~ 5-15 nm) amorphous Si films. We demonstrated a narrow bandwidth (~17 nm) super absorber with 97% maximum absorption with a performance comparable to nanostructure/nanoparticle-based super absorbers. We also investigated transmission filters in which different colors can be obtained by controlling the spacer thickness of silicon dioxide or amorphous silicon. With measured performance of transmission peak intensity reaching 60% and a narrow-band of ~ 40 nm, our color filters exceed the performance of widely studied plasmonic nanohole array based color filters and make a good candidate for large-area narrow-band photodetection devices. Such plasmonic loss incorporated Fabry-Perot cavities using ultra-thin metallic or semiconductor films could suggest active and practical applications in spectrally selective optical (color and absorber) filters, optoelectronic devices with controlled bandwidth such as narrow-band photodetectors, and light-emitting devices.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128689827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Tawa, Chisato Sasakawa, Shohei Yamamura, Izumi Shibata, M. Kataoka
A plasmonic chip which is a metal coated substrate with grating structure can provide the enhanced fluorescence by the grating-coupled surface plasmon field. In our previous studies, bright epi-fluorescence microscopic imaging of neuron cells and sensitive immunosesnsing have been reported. In this study, two kinds of breast cancer cells, MCF-7 and MDA-MB231, were observed with epi-fluorescence microscope on the plasmonic chip with 2D hole-arrays . They were multicolor stained with 4', 6-diamidino-2-phenylindole (DAPI) and allophycocyanin (APC)-labeled anti-epithelial cell adhesion molecule (EpCAM) antibody. Our plasmonic chip provided the brighter fluorescence images of these cells compared with the glass slide. Even in the cells including few EpCAM, the distribution of EpCAM was clearly observed in the cell membrane. It was found that the plasmonic chip can be one of the powerful tools to detect the marker protein existing around the chip surface even at low concentration.
{"title":"Multicolor fluorescence microscopic imaging of cancer cells on the plasmonic chip (Presentation Recording)","authors":"K. Tawa, Chisato Sasakawa, Shohei Yamamura, Izumi Shibata, M. Kataoka","doi":"10.1117/12.2186276","DOIUrl":"https://doi.org/10.1117/12.2186276","url":null,"abstract":"A plasmonic chip which is a metal coated substrate with grating structure can provide the enhanced fluorescence by the grating-coupled surface plasmon field. In our previous studies, bright epi-fluorescence microscopic imaging of neuron cells and sensitive immunosesnsing have been reported. In this study, two kinds of breast cancer cells, MCF-7 and MDA-MB231, were observed with epi-fluorescence microscope on the plasmonic chip with 2D hole-arrays . They were multicolor stained with 4', 6-diamidino-2-phenylindole (DAPI) and allophycocyanin (APC)-labeled anti-epithelial cell adhesion molecule (EpCAM) antibody. Our plasmonic chip provided the brighter fluorescence images of these cells compared with the glass slide. Even in the cells including few EpCAM, the distribution of EpCAM was clearly observed in the cell membrane. It was found that the plasmonic chip can be one of the powerful tools to detect the marker protein existing around the chip surface even at low concentration.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115905768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Rumbles, O. Reid, Jaehong Park, Jessica Ramirez, H. Marsh, Tyler T. Clikeman
With increasing knowledge of the role of the different phases in the bulk heterojunction organic solar cell, the primary site for charge generation is now considered to be the mixed phase, and not the clean interface between neat polymer and neat fullerene. To gain a better understanding of the primary charge generating and recombination steps in this region of the system, we focus our studies on the role of the solid-state microstructure of neat polymers and light-doping of these polymers with a variety of electron-accepting dopants at low concentration. This presentation will describe some recent work on the doping of polythiophene and polyfluorene derivatives with fullerenes, phthalocyanines and perylenes, which provide a range of reduction potentials that serve to control the driving force for electron transfer processes. Results from flash photolysis, time-resolved microwave conductivity (fp-TRMC), femtosecond transient absorption spectroscopy (fTA) and photoluminescence spectroscopy will be presented.
{"title":"Photo-induced electron transfer processes in doped conjugated polymer films (Presentation Recording)","authors":"G. Rumbles, O. Reid, Jaehong Park, Jessica Ramirez, H. Marsh, Tyler T. Clikeman","doi":"10.1117/12.2187688","DOIUrl":"https://doi.org/10.1117/12.2187688","url":null,"abstract":"With increasing knowledge of the role of the different phases in the bulk heterojunction organic solar cell, the primary site for charge generation is now considered to be the mixed phase, and not the clean interface between neat polymer and neat fullerene. To gain a better understanding of the primary charge generating and recombination steps in this region of the system, we focus our studies on the role of the solid-state microstructure of neat polymers and light-doping of these polymers with a variety of electron-accepting dopants at low concentration. This presentation will describe some recent work on the doping of polythiophene and polyfluorene derivatives with fullerenes, phthalocyanines and perylenes, which provide a range of reduction potentials that serve to control the driving force for electron transfer processes. Results from flash photolysis, time-resolved microwave conductivity (fp-TRMC), femtosecond transient absorption spectroscopy (fTA) and photoluminescence spectroscopy will be presented.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"9549 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130143897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Piqué, N. Charipar, Heungsoo Kim, E. Breckenfeld, S. Mathews
The use of metamaterials structures has been the subject of extensive discussions given their wide range of applications. However, a large fraction of the work available to date has been limited to simulations and proof-of-principle demonstrations. One reason for the limited success inserting these structures into functioning systems and real-world applications is the high level of complexity involved in their fabrication. Direct-write processes are ideally suited for the fabrication of arbitrary periodic and aperiodic structures found in most metamaterial and plasmonic designs. For these applications, laser-based processes offer numerous advantages since they can be applied to virtually any surface over a wide range of scales. Furthermore, laser direct-write or LDW allows the precise deposition and/or removal of material thus enabling the fabrication of novel metamaterial designs. This presentation will show examples of metamaterial and plasmonic structures developed at the Naval Research Lab using LDW, and discuss the benefits of laser processing for these applications. This work was sponsored by The Office of Naval Research.
{"title":"Laser processing of metamaterial structures (Presentation Recording)","authors":"A. Piqué, N. Charipar, Heungsoo Kim, E. Breckenfeld, S. Mathews","doi":"10.1117/12.2191645","DOIUrl":"https://doi.org/10.1117/12.2191645","url":null,"abstract":"The use of metamaterials structures has been the subject of extensive discussions given their wide range of applications. However, a large fraction of the work available to date has been limited to simulations and proof-of-principle demonstrations. One reason for the limited success inserting these structures into functioning systems and real-world applications is the high level of complexity involved in their fabrication. Direct-write processes are ideally suited for the fabrication of arbitrary periodic and aperiodic structures found in most metamaterial and plasmonic designs. For these applications, laser-based processes offer numerous advantages since they can be applied to virtually any surface over a wide range of scales. Furthermore, laser direct-write or LDW allows the precise deposition and/or removal of material thus enabling the fabrication of novel metamaterial designs. This presentation will show examples of metamaterial and plasmonic structures developed at the Naval Research Lab using LDW, and discuss the benefits of laser processing for these applications. This work was sponsored by The Office of Naval Research.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131062306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
van der Waals (vdW) crystals consist of individual atomic planes coupled by vdW interaction, similar to graphene monolayers in bulk graphite. We investigated van der Waals heterostructures assembled from atomically thin layers of graphene and hexagonal boron nitride (hBN). We launched, detected and imaged plasmonic, phonon polaritonic and hybrid plasmon-phonon polariton waves in a setting of an antenna based nano-infrared apparatus. Hyperbolic phonon polaritons in hBN enabled sub-diffractional focusing in infrared frequencies. Because electronic, plasmonic and phonon polaritonic properties in van der Waals heterstructures are intertwined, gate voltage and/or details of layer assembly enable efficient control of nano-photonic effects.
{"title":"Nano-photonic phenomena in van der Waals heterostructures (Presentation Recording)","authors":"D. Basov","doi":"10.1117/12.2189749","DOIUrl":"https://doi.org/10.1117/12.2189749","url":null,"abstract":"van der Waals (vdW) crystals consist of individual atomic planes coupled by vdW interaction, similar to graphene monolayers in bulk graphite. We investigated van der Waals heterostructures assembled from atomically thin layers of graphene and hexagonal boron nitride (hBN). We launched, detected and imaged plasmonic, phonon polaritonic and hybrid plasmon-phonon polariton waves in a setting of an antenna based nano-infrared apparatus. Hyperbolic phonon polaritons in hBN enabled sub-diffractional focusing in infrared frequencies. Because electronic, plasmonic and phonon polaritonic properties in van der Waals heterstructures are intertwined, gate voltage and/or details of layer assembly enable efficient control of nano-photonic effects.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131161073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dielectric optical antenna resonators have recently emerged as a viable alternative to plasmonic resonators for metamaterials and nanophotonic devices, due to their ability to support multipolar Mie resonances with low losses. In this work, we experimentally investigate the mid-infrared Mie resonances in Si and Ge subwavelength spherical particles. In particular, we leverage the electronic and optical properties of these semiconductors in the mid-infrared range to design and tune Mie resonators through free-carrier refraction. Si and Ge semiconductor spheres of varying sizes of 0.5-4 μm were fabricated using femtosecond laser ablation. Using single particle infrared spectroscopy, we first demonstrate size-dependent Si and Ge Mie resonances spanning the entire mid-infrared (2-16 μm) spectral range. Subsequently we show that the Mie resonances can be tuned by varying material properties rather than size or geometry. We experimentally demonstrate doping-dependent resonance frequency shifts that follow simple Drude models of free-carrier refraction. We show that Ge particles exhibit a stronger doping dependence than Si due to the smaller effective mass of the free carriers. Using the unique size and doping dispersion of the electric and magnetic dipole modes, we identify and demonstrate a size regime where these modes are spectrally overlapping. We also demonstrate the emergence of plasmonic resonances for high doping levels and long wavelengths. These findings demonstrate the potential for tuning infrared semiconductor Mie resonances by optically or electrically modulating charge carrier densities, thus providing an excellent platform for tunable electromagnetic metamaterials.
{"title":"Properties of infrared doped semiconductor Mie resonators (Presentation Recording)","authors":"T. Lewi, P. Iyer, N. Butakov, J. Schuller","doi":"10.1117/12.2187292","DOIUrl":"https://doi.org/10.1117/12.2187292","url":null,"abstract":"Dielectric optical antenna resonators have recently emerged as a viable alternative to plasmonic resonators for metamaterials and nanophotonic devices, due to their ability to support multipolar Mie resonances with low losses. In this work, we experimentally investigate the mid-infrared Mie resonances in Si and Ge subwavelength spherical particles. In particular, we leverage the electronic and optical properties of these semiconductors in the mid-infrared range to design and tune Mie resonators through free-carrier refraction. Si and Ge semiconductor spheres of varying sizes of 0.5-4 μm were fabricated using femtosecond laser ablation. Using single particle infrared spectroscopy, we first demonstrate size-dependent Si and Ge Mie resonances spanning the entire mid-infrared (2-16 μm) spectral range. Subsequently we show that the Mie resonances can be tuned by varying material properties rather than size or geometry. We experimentally demonstrate doping-dependent resonance frequency shifts that follow simple Drude models of free-carrier refraction. We show that Ge particles exhibit a stronger doping dependence than Si due to the smaller effective mass of the free carriers. Using the unique size and doping dispersion of the electric and magnetic dipole modes, we identify and demonstrate a size regime where these modes are spectrally overlapping. We also demonstrate the emergence of plasmonic resonances for high doping levels and long wavelengths. These findings demonstrate the potential for tuning infrared semiconductor Mie resonances by optically or electrically modulating charge carrier densities, thus providing an excellent platform for tunable electromagnetic metamaterials.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121956973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The co-sputtered Cu-Si-O and Cu-Ge-O thin films were prepared using reactive DC, pulse DC and modulated pulse power magnetron sputtering (MPPMS) on two separate Cu and Si or Cu and Ge targets simultaneously. The powers on each target and Oxygen/Argon flow ratio f(O2) were varied to have different stoichiometies determined by XPS. The film thickness, refractive index n and extinction coefficient k were extracted from in situ ellipsometry and the reactive plasma discharge was monitored by optical emission spectroscopy in real time during film growth. The grazing incident x-ray diffraction measurements reveal that the films deposited at low f(O2) have the nanocrystalline structure of cuprous Cu2O with diffraction peaks of (111) and (200). The films deposited at high f(O2) (≥ 1) have cupric oxide CuO phase. The optical constant n and k, film density and band gap of the co-sputtered film were investigated and determined by in situ ellipsometry, X-ray reflectivity and UV-Vis-NIR spectroscopy. Their structural, chemical and optical properties are able to be tuned by incorporating Cu2O, CuO and the mixtures of them into Silicon oxide or Germanium oxide matrix with varying target powers and oxygen/Argon ratio for applications in optical coatings and optical filters.
{"title":"Optical and structural properties of co-sputtered Cu-Si-O and Cu-Ge-O thin films (Presentation Recording)","authors":"Lirong Sun, N. Murphy, John G. Jones, J. Grant","doi":"10.1117/12.2188902","DOIUrl":"https://doi.org/10.1117/12.2188902","url":null,"abstract":"The co-sputtered Cu-Si-O and Cu-Ge-O thin films were prepared using reactive DC, pulse DC and modulated pulse power magnetron sputtering (MPPMS) on two separate Cu and Si or Cu and Ge targets simultaneously. The powers on each target and Oxygen/Argon flow ratio f(O2) were varied to have different stoichiometies determined by XPS. The film thickness, refractive index n and extinction coefficient k were extracted from in situ ellipsometry and the reactive plasma discharge was monitored by optical emission spectroscopy in real time during film growth. The grazing incident x-ray diffraction measurements reveal that the films deposited at low f(O2) have the nanocrystalline structure of cuprous Cu2O with diffraction peaks of (111) and (200). The films deposited at high f(O2) (≥ 1) have cupric oxide CuO phase. The optical constant n and k, film density and band gap of the co-sputtered film were investigated and determined by in situ ellipsometry, X-ray reflectivity and UV-Vis-NIR spectroscopy. Their structural, chemical and optical properties are able to be tuned by incorporating Cu2O, CuO and the mixtures of them into Silicon oxide or Germanium oxide matrix with varying target powers and oxygen/Argon ratio for applications in optical coatings and optical filters.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122035967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Smalley, F. Vallini, B. Kanté, Shiva Shahin, C. Riley, Y. Fainman
Using effective medium theory (EMT), Bloch’s theorem (BT), and the transfer matrix method (TMM), we analyze the possibility of gain-enhanced transmission in metamaterials with hyperbolic dispersion at telecommunication frequencies. We compare different combinations of dissipative metals and active dielectrics, including noble metals, transparent conducting oxides (TCO), III-V compounds, and solid-state dopants. We find that both indium gallium arsenide phosphide (InGaAsP) and erbium-doped silica (Er:SiO2), when combined with silver, show promise as a platform for demonstration of pump-dependent transmission. On the other hand, when these active dielectrics are combined with aluminum-doped zinc oxide (AZO), a low-loss TCO, gain-enhanced transmission is negligible. Results based on EMT are compared to the more accurate BT and TMM. When losses are ignored, quantitative agreement between these analytical techniques is observed near the center of the first Brillouin zone of a one-dimensional periodic structure. Including realistic levels of loss and gain, however, EMT predictions become overly optimistic compared to BT and TMM. We also discuss the limitations to assumptions inherent to EMT, BT, and TMM, and suggest avenues for future analysis.
{"title":"Gain-enhanced hyperbolic metamaterials at telecommunication frequencies (Presentation Recording)","authors":"J. Smalley, F. Vallini, B. Kanté, Shiva Shahin, C. Riley, Y. Fainman","doi":"10.1117/12.2187266","DOIUrl":"https://doi.org/10.1117/12.2187266","url":null,"abstract":"Using effective medium theory (EMT), Bloch’s theorem (BT), and the transfer matrix method (TMM), we analyze the possibility of gain-enhanced transmission in metamaterials with hyperbolic dispersion at telecommunication frequencies. We compare different combinations of dissipative metals and active dielectrics, including noble metals, transparent conducting oxides (TCO), III-V compounds, and solid-state dopants. We find that both indium gallium arsenide phosphide (InGaAsP) and erbium-doped silica (Er:SiO2), when combined with silver, show promise as a platform for demonstration of pump-dependent transmission. On the other hand, when these active dielectrics are combined with aluminum-doped zinc oxide (AZO), a low-loss TCO, gain-enhanced transmission is negligible. Results based on EMT are compared to the more accurate BT and TMM. When losses are ignored, quantitative agreement between these analytical techniques is observed near the center of the first Brillouin zone of a one-dimensional periodic structure. Including realistic levels of loss and gain, however, EMT predictions become overly optimistic compared to BT and TMM. We also discuss the limitations to assumptions inherent to EMT, BT, and TMM, and suggest avenues for future analysis.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123991499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyuk‐Jun Kwon, Woong Choi, M. Oh, Sunkook Kim, C. Grigoropoulos
Laser enables the achievement of superb interfacial characteristics between electrode and semiconducting material contact surface and is also useful for a reduction in contact resistance. The irradiation of a pulsed laser with high energy density and short wavelength onto the electrodes leads to thermal annealing at the locally confined small area that needs high temperature without inflicting thermal damage. This contrasts conventional thermal annealing that affects the entire panel, including unwanted areas in which the annealing process should be excluded. We demonstrate that mechanically flexible and optically transparent (more than 81% transmittance in visible wavelength) multilayered molybdenum disulfide (MoS2) thin-film transistors (TFTs) in which the source/drain electrodes are selectively annealed using picosecond laser achieve the enhancement of device performance without plastic deformation, such as higher mobility, increased output resistance, and decreased subthreshold swing. Numerical thermal simulation for the temperature distribution, transmission electron microscopy (TEM) analysis, current-voltage measurements, and contact-free mobility extracted from the Y-function method (YFM) enable understanding of the compatibility and the effects of pulsed laser annealing process; the enhanced performance originated not only from a decrease in the Schottky barrier effect at the contact, but also an improvement of the channel interface. Furthermore, these results show that the laser annealing can be a promising technology to build up a high performance transparent and flexible electronics.
{"title":"Pulsed laser annealing for advanced performance of mechanically flexible and optically transparent multilayer MoS2 transistors (Presentation Recording)","authors":"Hyuk‐Jun Kwon, Woong Choi, M. Oh, Sunkook Kim, C. Grigoropoulos","doi":"10.1117/12.2192024","DOIUrl":"https://doi.org/10.1117/12.2192024","url":null,"abstract":"Laser enables the achievement of superb interfacial characteristics between electrode and semiconducting material contact surface and is also useful for a reduction in contact resistance. The irradiation of a pulsed laser with high energy density and short wavelength onto the electrodes leads to thermal annealing at the locally confined small area that needs high temperature without inflicting thermal damage. This contrasts conventional thermal annealing that affects the entire panel, including unwanted areas in which the annealing process should be excluded. We demonstrate that mechanically flexible and optically transparent (more than 81% transmittance in visible wavelength) multilayered molybdenum disulfide (MoS2) thin-film transistors (TFTs) in which the source/drain electrodes are selectively annealed using picosecond laser achieve the enhancement of device performance without plastic deformation, such as higher mobility, increased output resistance, and decreased subthreshold swing. Numerical thermal simulation for the temperature distribution, transmission electron microscopy (TEM) analysis, current-voltage measurements, and contact-free mobility extracted from the Y-function method (YFM) enable understanding of the compatibility and the effects of pulsed laser annealing process; the enhanced performance originated not only from a decrease in the Schottky barrier effect at the contact, but also an improvement of the channel interface. Furthermore, these results show that the laser annealing can be a promising technology to build up a high performance transparent and flexible electronics.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128585383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zizhuo Liu, Serkan Bütün, E. Palacios, Koray Aydin
Enhanced transmission of light through nanostructures has always been of great interest in the field of plasmonics and nanophotonics. With the aid of near-field effects, the transmission of the electromagnetic waves can be enhanced or suppressed. Much of the work on enhanced transmission has been shown to be frequency-selective. However it is possible to increase the transmission over a large frequency range by using graphene, which has shown broadband properties in many applications. Here, we propose enhanced transmission in wire grid gold structure making use of continuous graphene sheets. We use finite-difference time-domain simulations to study the optical properties of this graphene-metal hybrid structure at mid infrared (mid-IR) wavelengths. The grating structure in wire grid gold provides an ideal platform to match the momentum and excite the surface plasmon polaritons (SPPs) in monolayer graphene. Our numerical calculations show that the local electromagnetic field around the graphene is largely enhanced due to surface plasmons. Moreover, with the highly confined SPPs coupling with the incident light, the transmission through the whole structure can be broadly enhanced in the mid infrared region. We also analyze the effect of the spectrum with different periods and gold nanowire widths to evaluate the size effects of the plasmons in graphene. In addition, by tuning the Fermi level, one can control the wavelength range at which the transmission is enhanced. The mechanism of the enhancement will be explained in the calculated electric field distribution. And we will also highlight the opportunities of graphene for applications such as tunable transmission and active photonic modulator.
{"title":"Enhanced infrared transmission from gold wire-grid arrays via surface plasmons in continuous graphene (Presentation Recording)","authors":"Zizhuo Liu, Serkan Bütün, E. Palacios, Koray Aydin","doi":"10.1117/12.2186872","DOIUrl":"https://doi.org/10.1117/12.2186872","url":null,"abstract":"Enhanced transmission of light through nanostructures has always been of great interest in the field of plasmonics and nanophotonics. With the aid of near-field effects, the transmission of the electromagnetic waves can be enhanced or suppressed. Much of the work on enhanced transmission has been shown to be frequency-selective. However it is possible to increase the transmission over a large frequency range by using graphene, which has shown broadband properties in many applications. Here, we propose enhanced transmission in wire grid gold structure making use of continuous graphene sheets. We use finite-difference time-domain simulations to study the optical properties of this graphene-metal hybrid structure at mid infrared (mid-IR) wavelengths. The grating structure in wire grid gold provides an ideal platform to match the momentum and excite the surface plasmon polaritons (SPPs) in monolayer graphene. Our numerical calculations show that the local electromagnetic field around the graphene is largely enhanced due to surface plasmons. Moreover, with the highly confined SPPs coupling with the incident light, the transmission through the whole structure can be broadly enhanced in the mid infrared region. We also analyze the effect of the spectrum with different periods and gold nanowire widths to evaluate the size effects of the plasmons in graphene. In addition, by tuning the Fermi level, one can control the wavelength range at which the transmission is enhanced. The mechanism of the enhancement will be explained in the calculated electric field distribution. And we will also highlight the opportunities of graphene for applications such as tunable transmission and active photonic modulator.","PeriodicalId":432358,"journal":{"name":"SPIE NanoScience + Engineering","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127320641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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