SPIE Micro + Nano Materials, Devices, and Applications最新文献

{"title":"Resonance breakdown of dielectric resonator antennas on ground plane at visible frequencies","authors":"C. Zou, W. Withayachumnankul, L. Zou, C. Fumeaux","doi":"10.1117/12.2202422","DOIUrl":"https://doi.org/10.1117/12.2202422","url":null,"abstract":"Nanoscale dielectric resonator antennas (DRAs) are promising elements for constructing the next generation of efficient and compact optical devices. Their efficient light manipulation capability underpinned by electric and magnetic resonances at visible frequencies is appealing for optical metasurfaces with various functions such as anomalous re ection, polarization conversion and surface plasmon coupling. To realize these functions, the resonance properties of the individual DRA elements are of critical importance. In this paper, we study the resonance breakdown of nanoscale cylindrical DRAs on metallic substrates. By gradually increasing the relative permittivity of DRAs on a metallic ground plane from low to high values, we observe two types of resonance breakdown and on that basis we can define a permittivity range for efficient resonance. More specifically, the resonance breakdown occuring at low DRA permittivities is a result of weak confinement and excessive radiation loss. The resonance breakdown at high DRA permittivities is a result of an elevated plasmonic loss at the metal- dielectric interface when the negative permittivity of the metal and the positive permittivity of the dielectric material have matched in their absolute values. The latter breakdown can be avoided by inserting a thin dielectric spacer with a low permittivity between the metal and dielectric. This study suggests important considerations for designing dielectric resonator metasurfaces at the visible frequencies.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114710991","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}

{"title":"Nanostructured metallic rear reflectors for thin solar cells: balancing parasitic absorption in metal and large-angle scattering","authors":"Claire E. R. Disney, S. Pillai, M. Green","doi":"10.1117/12.2203289","DOIUrl":"https://doi.org/10.1117/12.2203289","url":null,"abstract":"Rear reflectors for solar cells comprised of metal films with periodic arrays of nanoscale features on their surface can provide significantly enhanced light trapping in the absorber layer. However these structures can also result in significantly increased parasitic absorption into the metal layer at various wavelengths of light. Conversely these highly absorbing resonances can also coincide with the wavelengths which display the largest enhancement to the cell’s photocurrent. As such it is important to understand the underlying causes for such photocurrent enhancements and losses in the metal in order to design the optimum structure for use. 3D Finite-difference-time-domain simulations have been used to model a variety of structures and analyze the spatial distribution of absorption within different materials which make up the structure, the angles at which light will be scattered from the rear surface, as well as the idealized short circuit current from each structure integrated across the AM1.5 spectrum. These reveal the properties of these modes at resonant wavelengths at which absorption into both materials is enhanced. Despite the enhanced coupling of light into the metal at these wavelengths, the amount of light scattered back into the absorber at large angles is also significantly boosted. For a large variety of geometries, the impact of this large angle scattering dominates leading to significant increases to a cell’s photocurrent. Our simulations allow us to understand the contributions of multiple plasmonic effects occurring in such structures, allowing selection of the most suitable geometries to achieve large-angle scattering in a desired wavelength range.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126563533","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}

{"title":"Wafer-scale epitaxial graphene on SiC for sensing applications","authors":"Mikael C. F. Karlsson, Qin Wang, Yichen Zhao, Wei Zhao, M. Toprak, T. Iakimov, A.M.M. Ali, R. Yakimova, M. Syväjärvi, I. Ivanov","doi":"10.1117/12.2202440","DOIUrl":"https://doi.org/10.1117/12.2202440","url":null,"abstract":"The epitaxial graphene-on-silicon carbide (SiC-G) has advantages of high quality and large area coverage owing to a natural interface between graphene and SiC substrate with dimension up to 100 mm. It enables cost effective and reliable solutions for bridging the graphene-based sensors/devices from lab to industrial applications and commercialization. In this work, the structural, optical and electrical properties of wafer-scale graphene grown on 2’’ 4H semi-insulating (SI) SiC utilizing sublimation process were systemically investigated with focus on evaluation of the graphene’s uniformity across the wafer. As proof of concept, two types of glucose sensors based on SiC-G/Nafion/Glucose-oxidase (GOx) and SiC-G/Nafion/Chitosan/GOx were fabricated and their electrochemical properties were characterized by cyclic voltammetry (CV) measurements. In addition, a few similar glucose sensors based on graphene by chemical synthesis using modified Hummer’s method were also fabricated for comparison.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127611588","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}

{"title":"CMOS compatible fabrication process of MEMS resonator for timing reference and sensing application","authors":"D. H. Huynh, P. Nguyen, T. Nguyen, S. Skafidas, R. Evans","doi":"10.1117/12.2202532","DOIUrl":"https://doi.org/10.1117/12.2202532","url":null,"abstract":"Frequency reference and timing control devices are ubiquitous in electronic applications. There is at least one resonator required for each of this device. Currently electromechanical resonators such as crystal resonator, ceramic resonator are the ultimate choices. This tendency will probably keep going for many more years. However, current market demands for small size, low power consumption, cheap and reliable products, has divulged many limitations of this type of resonators. They cannot be integrated into standard CMOS (Complement metaloxide- semiconductor) IC (Integrated Circuit) due to material and fabrication process incompatibility. Currently, these devices are off-chip and they require external circuitries to interface with the ICs. This configuration significantly increases the overall size and cost of the entire electronic system. In addition, extra external connection, especially at high frequency, will potentially create negative impacts on the performance of the entire system due to signal degradation and parasitic effects. Furthermore, due to off-chip packaging nature, these devices are quite expensive, particularly for high frequency and high quality factor devices. To address these issues, researchers have been intensively studying on an alternative for type of resonator by utilizing the new emerging MEMS (Micro-electro-mechanical systems) technology. Recent progress in this field has demonstrated a MEMS resonator with resonant frequency of 2.97 GHz and quality factor (measured in vacuum) of 42900. Despite this great achievement, this prototype is still far from being fully integrated into CMOS system due to incompatibility in fabrication process and its high series motional impedance. On the other hand, fully integrated MEMS resonator had been demonstrated but at lower frequency and quality factor. We propose a design and fabrication process for a low cost, high frequency and a high quality MEMS resonator, which can be integrated into a standard CMOS IC. This device is expected to operate in hundreds of Mhz frequency range; quality factor surpasses 10000 and series motional impedance low enough that could be matching into conventional system without enormous effort. This MEMS resonator can be used in the design of many blocks in wireless and RF (Radio Frequency) systems such as low phase noise oscillator, band pass filter, power amplifier and in many sensing application.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114992969","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}

{"title":"Transforming polarisation to wavelength via two-colour quantum dot plasmonic enhancement","authors":"T. James, P. Mulvaney, T. Davis, A. Roberts","doi":"10.1117/12.2199045","DOIUrl":"https://doi.org/10.1117/12.2199045","url":null,"abstract":"Optical nano-antennas have become a hot topic in photonics research recently due to their ability to manipulate electromagnetic radiation on the subwavelength scale. Of particular interest is the application of optical nano-antennas to enhancement of quantum sources such as semiconductor Quantum Dots (QD) and Nitrogen Vacancy (NV) centers in nano-diamond. Much like their Radio Frequency (RF) cousins, optical nano-antennas are able to enhance and direct radiation from a localized source in the near-field of the antenna to the far-field. The work reported here exploits RF antenna designs by applying them to the development of optical nano-antennas for enhancement of multiple semiconductor QDs. In particular, the Vee antenna design, commonly used in improvised military RF applications, is utilized in this work as an optical nano-antenna to enable the selective excitation of two different color QDs via polarization control. The Vee antenna has two bright resonant modes in the visible spectrum, typically spectrally separated by approximately 50 nm, which are excited by orthogonal polarizations of the excitation field. Using these two resonant modes of the Vee antenna, two different color QDs can be selectively enhanced. The Vee antennas are fabricated with E-beam Lithography using aluminum as the antenna material on a multilayer SiO2/Al/glass substrate. The Vee antenna design consists of two dipole antennas, orientated at 90° to each other, where the gap between the antennas and the thickness of the SiO2 spacer layer is used to tune the spectral separation of the orthogonal resonances.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125591353","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}

{"title":"Bubble-induced acoustic mixing in a microfluidic device","authors":"Huaying Chen, K. Petkovic-Duran, M. Best, Yonggang Zhu","doi":"10.1117/12.2202484","DOIUrl":"https://doi.org/10.1117/12.2202484","url":null,"abstract":"Homogeneous and fast mixing of samples at microscale is a critical requirement for successful applications of microfluidics in biochemical analysis, chemical synthesis, drug delivery and nanomaterial synthesis. This paper reports the optimisation of bubble-induced mixing in a microfluidic device in terms of voltage, driving frequency, piezo transducer position and PDMS thickness. The microfluidic device consists of a microwell (with the diameter of 1mm and volume of ~95 nL) with two rectangular bubble traps (400×400μm) on both sides of the well. After the injection of liquid, air bubbles were spontaneously trapped in two rectangular traps. When the frequency of a piezo was equal to the resonance frequency of air bubbles, strong liquid recirculation formed (so called acoustic microstreaming) in the vicinity of the interface of air bubbles and water. The acoustic induced flow of microbeads and mixing of water and fluorescence dye were imaged to study the mixing efficiency. For a given voltage and PDMS thickness, when the piezo was placed on top of the well, the mixing was most vigorous. For a given frequency, the mixing efficiency was directly proportional to the voltage (4-20V) and inversely proportional to the PDMS thickness (0.3-2mm). When the frequency driving the piezo was approaching the resonance frequency of air bubbles, the mixing efficiency was maximal, while when it was far away from the resonance frequency of air bubbles, the mixing efficiency was much lower. This work provides guidance to the design and the application of bubble-induced acoustic mixing in microfluidics.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128037586","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}

{"title":"Nanosphere lithography for improved absorption in thin crystalline silicon solar cells","authors":"Yuan-Chih Chang, D. Payne, M. Pollard, S. Pillai, D. Bagnall","doi":"10.1117/12.2202453","DOIUrl":"https://doi.org/10.1117/12.2202453","url":null,"abstract":"Over the last decade, plasmonic nanoparticle arrays have been extensively studied for their light trapping potential in thin film solar cells. However, the commercial use of such arrays has been limited by complex and expensive fabrication techniques such as e-beam lithography. Nanosphere lithography (NSL) is a promising low-cost alternative for forming regular arrays of nanoscale features. Here, we use finite-difference time-domain (FDTD) simulations to determine the optical enhancement due to nanosphere arrays embedded at the rear of a complete thin film device. Array parameters including the nanosphere pitch and diameter are explored, with the FDTD model itself first validated by comparing simulations of Ag nanodisc arrays with optical measurements of pre-existing e-beam fabricated test structures. These results are used to guide the development of a nanosphere back-reflector for 20 μm thin crystalline silicon cells. The deposition of polystyrene nanosphere monolayers is optimized to provide uniform arrays, which are subsequently incorporated into preliminary, proof of concept device structures. Absorption and photoluminescence measurements clearly demonstrate the potential of nanosphere arrays for improving the optical response of a solar cell using economical and scalable methods.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122456195","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}

{"title":"Novel plasmonic materials to improve thin film solar cells efficiency","authors":"N. Saiprasad, A. Boretti, L. Rosa, S. Castelletto","doi":"10.1117/12.2202475","DOIUrl":"https://doi.org/10.1117/12.2202475","url":null,"abstract":"Thin film solar cells have been widely studied with the focus on how to improve light trapping mechanism and enhance the overall photon-electrons conversion efficiency. The effect of novel plasmonic materials based on wide bandgap semiconductors, such as metals heavily doped zinc oxides and metal nitrides, are here studied in relation to their potential use in thin film solar cells. Here, we show that metal nitrides can play similar roles as gold nanoparticles on a surface of a Si-thin film solar cell, possibly without introducing excessive dissipative absorption, while metals doped zinc oxide nanoparticles could significantly improve the efficiency of thin film solar cells.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132634788","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}

{"title":"Systematic assessment of blood circulation time of functionalized upconversion nanoparticles in the chick embryo","authors":"A. Nadort, L. Liang, E. Grebenik, Anna E Guller, Yiqing Lu, Yi Qian, E. Goldys, A. Zvyagin","doi":"10.1117/12.2202449","DOIUrl":"https://doi.org/10.1117/12.2202449","url":null,"abstract":"Nanoparticle-based delivery of drugs and contrast agents holds great promise in cancer research, because of the increased delivery efficiency compared to ‘free’ drugs and dyes. A versatile platform to investigate nanotechnology is the chick embryo chorioallantoic membrane tumour model, due to its availability (easy, cheap) and accessibility (interventions, imaging). In our group, we developed this model using several tumour cell lines (e.g. breast cancer, colon cancer). In addition, we have synthesized in-house silica coated photoluminescent upconversion nanoparticles with several functional groups (COOH, NH2, PEG). In this work we will present the systematic assessment of their in vivo blood circulation times. To this end, we injected chick embryos grown ex ovo with the functionalized UCNPs and obtained a small amount of blood at several time points after injection to create blood smears The UCNP signal from the blood smears was quantified using a modified inverted microscope imaging set-up. The results of this systematic study are valuable to optimize biochemistry protocols and guide nanomedicine advancement in the versatile chick embryo tumour model.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126800692","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}

{"title":"A temperature-compensated optical fiber force sensor for minimally invasive surgeries","authors":"Z. Mo, W. Xu, N. Broderick, H. Chen","doi":"10.1117/12.2202539","DOIUrl":"https://doi.org/10.1117/12.2202539","url":null,"abstract":"Force sensing in minimally invasive surgery (MIS) is a chronic problem since it has an intensive magnetic resonance (MR) operation environment, which causes a high influence to traditional electronic force sensors. Optical sensor is a promising choice in this area because it is immune to MR influence. However, the changing temperature introduces a lot of noise signals to them, which is the main obstacle for optical sensing applications in MIS. This paper proposes a miniature temperature-compensated optical force sensor by using Fabry-Perot interference (FPI) principle. It can be integrated into medical tools’ tips and the temperature noise is decreased by using a reference FPI temperature sensor. An injection needle with embedded temperature-compensated FPI force sensor has been fabricated and tested. And the comparison between temperature-force simulation results and the temperature-force experiment results has been carried out.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128193504","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}