Nanophotonics and Optics
Biography: Jingxia Wang received both her BS and MS degrees in Polymer Chemistry from Qingdao University of Science and Technology in 1994 and 1997, respectively. Then, she received her PhD degree in Material Science from Tsinghua University in 2004. She worked as a postdoctoral fellow in Prof. Lei Jiang’s group in the Laboratory of Organic Solids in the Institute of Chemistry, Chinese Academy ofSciences (CAS) between 2004 and 2006. Acting as associate professor, she then joined Prof. Yanlin Song’s group in theLaboratory of Green Printing in the Institute of Chemistry, CAS, between 2006 and 2014. In 2014, she moved to the Technical Institute of Physics and Chemistry, CAS. Her research interest is focused on the fabrication and applications of colloidal PCs with superwettability. She has published more than 100 SCI Journal papers in the field. She is currently a full professor at the Technical Institute of Physics and Chemistry, CAS.
Abstract: Photonic crystals (PCs) demonstrate important applications in new optical devices owing to special property of light regulation. This paper presents a series of functional PCs based on its special wettability. As-prepared metal-organic (Pb(NO3)-COOH) PCs can achieve irreversible changes in color/morphology during the electrowetting process, developing a novel and simple water-lithography approach for the creation of the PC pattern. The close-cell carbon dots inverse opals, which prepared from organosilane-polymerized carbon dots and low temperature process, show unique lyophilic but nonwettable wettability. In addition, the special optical properties of the carbon dots endow the sample with tricolor-fluorescence, fluorescence enhancement and modulated optical limiting performance, making it well used in anti-fake pattern. A novel humidity-induced actuator is prepared by the gradient wettability of polyionic liquid inverse opals. Futhermore, Janus PC films can be obtained by asymmetric filling. The directional actuation and thermal shape memory function of PVDF PCs have been realized. A colloidal microarray with optical waveguide behavior is obtained by using a superwettability assembly of fluorescent dye particles. These works are of great significance for the preparation of multi-functional PC materials and new optical devices
Applications of Nanotechnology
Biography: Dr. Eepsita Priyadarshini is presently working as a postdoctoral fellow at School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India. She received her PhD degree in Biotechhnology from AcSIR, India in 2017. Her research interest includes synthesis of engineered nanoconjugates and quantum dots, development of nano-based sensors for therapeutic and diagnostic application, biocompatibility and antimicrobial studies of nanoparticles. Her contributions in basic sciences have resulted in a number of publications in reputed SCI journals and patents. She has extensively worked on development of metal nanoparticles based sensors for waste water treatment.
Abstract: Recently, nanoconjugates have gained significant attention because of their biocompatibility, stability and physicochemical properties. In this work, we aimed at synthesizing novel Au@CDs nanoconjugate with dual property of optical and fluorescence. The Au counterpart provided optical signal while the carbon dot acted as the fluorescence quencher or enhancer. Various analytical charecterization as TEM, UV-Visible spectroscopy, fluorescence spectroscopy, DLS and zeta potential was performed. Cytotoxicty assay against HeLa and HEK293 cell lines suggeted the potential non-toxic nature of the nanoconjugates. Bioimaging studies suggested that the Au@CD particles are entrapped in the cell interior signified by fluorescence signals. The nanoconjugates were found to be relatively safe to cells up to a concentration of 100 µg/ml.
We further analyzed the detection potential of the nanoconjugates against a number of analytes. A number of assays including selectivity, sensitivity and interference studies suggested the high selectivity of nanoconjugates towards cholesterol. On treating the nanoconjugates with cholesterol a vivid change in colour of reaction mixture from reddish to turbid white was observed. Simultaneously changes in absorption and fluorescence was found. While a red shift in the SPR peak was observed with increasing concentration of cholesterol, quenching in fluorescence intensity was found. A minimum detection limit of 0.12 ppm was observed.
The study thus suggests the development of an enzyme free assay for cholesterol by the use of biocompatible and aqueous soluble Au@CDs nanoconjugates, thereby eliminating the need of costly and lengthy sample preparation protocol.
Abstract: This study was designed to assess the efficacy, tolerability, and safety of
fluconazole (FLZ) loaded nanostructured lipid carrier (FLZ-NLC) given at 0.5%
daily for 8 followed at the 2st, 4nd, and 8th weeks in the treatment of tinea versicolor
(TV). The results showed that FLZ-NLCs were spherical in shape with an average
diameter of 239.7 ± 99.48 nm. The polydispersity index (PI) and zeta potential of
these nanoparticles were 0.234 ± 0.031 and −21.39 ± 0.051 respectively. Using the
CLSI document M27-A3 and M27-S4 susceptibility testing methodology, the
development of most strains was clearly visible after 24 h of incubation at 32 °C.
Using new formulation of FLZ leads to a significant decrease in MIC values for
strains of M. furfur against both FLZ and CTZ (P<0.05). The mean score at baseline
and weeks 2, 4, and 8 was 4.7, 3.2, 2.6, and 2.7, respectively and Erythema, pruritus,
and scaling were evaluated and improved over time (0 ¼ absent and 9 ¼ worst).
Global assessments mean scores were improved following a 2-week treatment
(0¼worse and 4¼excellent improvement): week 2: 1.7; week 4: 1.7; and week 8:
1.9. ), a significant difference between improvement trends was seen during weak 2
to 8. FlZ-NLCs based gel 0.5% showed better activity against Tinea versicolor than
Comercial colotrimazole cream 1%. It was concluded that new gel could be a
promising formulation for effective treatment of Tinea versicolor.
Electronic, Optical, and Magnetic Materials
Abstract: In the present work, pure and various concentration of dysprosium (0, 1, 3, 5%) doped SrTiO3 ceramics were synthesized by solid state reaction. The structural examination based on X-ray Diffraction (XRD) reveal the cubic perovskite of strontium titanate ceramics. Raman spectra justifies the formation of cubic perovskite structure and the presence of local disorder in the ceramics. Irregular morphology with ploy dispersed nature of the prepared ceramics were determined by scanning electron microscopy (SEM). Optical absorption studies demonstrate the intriguing visible range absorption and multi-color emission. Further, the band gap values are deliberated using UV and PL shows violet, green and blue emission at an excitation of 330nm. At room temperature strontium titanate is diamagnetic, on addition of Dy in SrTiO3 lattice exhibits anti-ferromagnetic signature. As the doping level increases due to Dy-Dy interaction anti-ferromagnetic signature is increased. The dielectric constant ε' value is very low, as the content of Dy increases in Sr-Ti-O lattice the constant value augmented and space charge polarization is present.
Materials Science-Fundamentals & Characterization
Biography: Jau Tang, an APS Fellow, is a distinguished professor in the Institute of Technological Sciences. His research areas include nanoscience, 4D electron microscopy, ultrafast phenomena, single-molecule spectroscopy, phase transitions, plasma hydrodynamics, optoelectronics, synthetic diamond growth, photo physics/chemistry and electron transfer reactions. He has served in several conference committees, and has received international awards including R&D 1000 Award. He received his Ph.D. degree from UC Berkeley. Prior to his returning to China, he has worked at Argonne National Lab, Bell Labs and Caltech.
Abstract: By combining high spatial and temporal resolution of 4D electron microscopy we have demonstrated its applications in nanoscience and nanotechnology. We are able to investigate ultrafast dynamics and atomic scale spatial resolution of nanomaterials which might help soling important issues in energy, environment and health related issues in modern society. In our 2015 Science paper we have used USEM (ultrafast scanning electron microscopy) ultrafast dynamics of photo-induced electrons and holes induced by fs laser in p-n semiconductor junctions. We have observed ballistic dynamics and gating mechanism of the depletion zone for the hot charged carriers at short times, rather than the more familiar carrier diffusion. Moreover, we have also observed THz plasma waves at high laser fluence due to Coulomb forces among carriers. In our another Science paper in 2017 and a paper in Science Advances we have studied photo-induced rotational and translational motion of single gold nanoparticles Using UTEM (ultrafast transmission electron microscopy) we observed ballistic motion with friction, yet at longer time scales abnormal diffusion with extremely fast diffusion was observed. We have identified steam nanobubbles generated on the laser-heated gold nanoparticles are the driving force for such fast dynamics. We have also investigated the processes of nucleation from the liquid phase to final crystallization of TiO2 nanoparticles to elucidate the mechanism. Eutectic reactions of alloys from GaAs nanowires encapped by a gold tip were also studied to improve understanding of the laser heating and heat transfer processes during superstructure formation of the alloy. In another work of USEM of graphene monolayer, we have observed dynamic spatial and temporal distributions of charged carrier, exhibiting a crater-shaped charge density map at high fluence and yet a Gaussian distribution at low fluence. We have attributed these phenomena to Auger-assisted charge recombination processes.
Biography: Dr. Xu received his PhD from the National University of Singapore (NUS). His current research areas are mainly focused on POSS-based functional hybrid materials, electrochromic conjugated polymers and aggregation-induced emission based materials and thermoelectric materials. He has published more than 150 papers and filed more than 30 patents, some of which has been licensed to companies. He contributed 7 chapters to polymer materials related books and also compiled a book on smart electrochromic materials and device. Now, he is a Principal Scientist in IMRE, A*STAR, Republic of Singapore. He also holds an adjunct Associate Professor in NUS.
Abstract: Conducting polymers have been attracted considerable attentions due to their exceptional benefits such as light-weight, low-cost, good electrical conductivity and good flexibility, making them as excellent candidates for a variety of organic electronics including organic light-emitting diode, organic thin-film transistor and organic photovoltaics. Recently, conducting conjugated polymers, for example, poly(3,4-ethylenedioxythiophene) (PEDOT) have been used for thermoelectrics applications. In general, the thermoelectric performance of a given material is principally accessed by the figure of merit ZT=S2𝜎T/, where S is the Seebeck coefficient, 𝜎 is the electrical conductivity, T is the absolute temperature and is the total thermal conductivity. Given that the thermoelectric properties of a large number of conducting polymers are not attractive to produce high performance devices, remarkable attempts have been made to enhance either the electrical conductivity or/and Seebeck coefficient.
This presentation will highlight our recent work in developing conducting polymers and their composites with different dopants such as carbon nanostructures and inorganic nanostructures, as well as different controllable treatment processes of these polymers and composites. In addition, the thermoelectric devices of conducting polymers were fabricated and their properties were fully characterized. As an example, a doped conducting polymer was post-treated with a series of dopants, and then was used to fabricate thermoelectric devices with desired thermoelectric properties.
Biography: Junwei Ye, Dr, Professor. In 2007, he graduated from the school of chemistry, Jilin University, and obtained his doctor's degree. He worked as a visiting scholar in the University of California, Los Angeles and the University of Dundee in the UK. At present, He works in Dalian University of Technology, and studies on resource chemistry and advanced functional materials. By designning organic and inorganic building block, many types of micro-/nano-structures with ordered aggregation and controllable morphologies were developed, and their applications in the fields of photoelectricity and environmental monitoring were invesitigated. He published more than 90 papers and authorized 15 patents.
Abstract: During the past decades, the outbreak of infectious diseases caused by certain microorganisms led to a serious problem for human health and environmental issues. Traditional disinfectors have some drawbacks of product break-down, toxicity and lack of long-term stability, so developing new antibacterial materials is attracted tremendous attention. As a new kind of antibacterial materials, metal organic coordination polymers exhibit high efficiency, long duration and wide spectrum antibacterial activity. Compared with the current commercial antimicrobials, the variable structures of the metal organic coordination polymer provides the possibility for controlling ion release, conducting the synergistic action of organic molecules and metal ions, and improving the antibacterial activity and biocompatibility. We designed and synthesized a series of zinc, copper, silver metal organic coordination polymers, and investigate the effect of structure and morphology on the antibacterial properties. These metal organic coordination polymers show excellent antibacterial activity on E. coli and S. aureus with the minimal inhibition concentrations of 15-30 ppm. This work demonstrates that metal-organic coordination polymers could be regarded as promising materials for antibacterial application in the fields of medical dressings, textile and industrial antibacterial film.
Biography: Mikhail D. Starostenkov – Professor, Doctor of Physical and Mathematical Sciences, Honored Scientist of the Russian Federation heads the scientific school on theory and computer modeling in condensed matter physics. Under his leadership, prepared 11 dissertations for the degree of Doctor of Physical and Mathematical Sciences and 60 PhD dissertations. Mikhail D. Starostenkov is an expert of the Ministry of Science and Higher Education, has a certificate «Outstanding contribution in reviewing» - Diploma from «Elsevier» publishing house editors (Amsterdam, Netherlands), in recognition of a contribution to the quality of the journal «Journal Alloys and Compounds». He is the chief editor of the journal «Fundamental’nye problemy sovremennogo materialovedenia (Basic Problems of Material Science (BPMS))», a member of the editorial board of the journal «Letters on Materials». He has published 11 monographs and over 600 articles in journals indexed in the Web of Science, Scopus, and other systems. Mikhail D. Starostenkov has over 30 grants. He actively takes part in international symposia and conferences in China, South Korea, USA, Canada, Italy, France, Norway and other countries.
Abstract: Using the CuPt alloy as an example, structural and superstructural transformations at the nanostructural level are investigated depending on the concentration of the components. The Cu-Pt system alloys when going into an ordered state (during the order-disorder phase transition) form a group of superstructures, such as L11 (rhombohedral based on fcc lattice), L13 (rhombohedral), L12 (based on fcc lattice), Cu3Pt5, CuPt7, Cu7Pt [1-3]. All of these superstructures are characterized by the appearance of a certain anisotropy in specific crystallographic directions. Such a property may be considered at the nanoscale as an element of shape-memory, or physical properties memory (for example, magnetic). Using Monte-Carlo computer simulation method a detailed analysis of possible nanostructures in the Cu-Pt system was carried out in this research. Conclusions and recommendations on the possible application of the detected properties are given. Other alloys may have similar characteristics.
Abstract: The main scientific approach of investigations based on forgotten classical interpretation (R. Cahn, R. Swalin, A. Cottrell etc) of free energy and mixing entropy as a latent work, produced by a system on the surroundings. Therefore configurational or mixing entropy, which is referred only to the state probability, naturally, has energy meaning. Hence it can potentially produce energy that is also confirmed by osmotic processes. Hence even in ideal mixing where is no visible changes in enthalpy of mixing, really two processes occur simultaneously and compensate each other. First process - the increase of average heat capacity (atomic oscillations) that needs heat or energy to remain temperature constant. And second opposite process – latent heat release by strengthening of interatomic bonds. That is why the novel class of alloys - high-entropy alloys has high mechanical properties.
Biography: Dr. Samson Mil’shtein is Professor of Electrical and Computer Engineering of UMass Lowell since 1987. During 1998-1999 he served as Assistant Dean of Engineering for Research, UMass Lowell, MA. From 1990 he is the director of the Advanced Electronic Technology Center.
His publication list carries over 270 publications, patents, and conference presentations. His current research work covers high speed quantum electronics, solar sell systems, bio-medical engineering.
In May 2015 Prof. S. Mil’shtein was elected as Member of Academy (Academician) of Natural Sciences of Kazakhstan Republic.
Abstract: In this manuscript, we present the design of the vertical ballistic MOSFET structure, capable to operate at 1THz. In future work, the redesigned MOSFET structure will be operational at 3 THz. The source to drain distance in vertical direction is 400Å. The cross-section of the device (seen from the top) is rectangular with dimensions of 600Å by 100µm, which allows to run a total current of 10 – 15mA/µm normalized to the thickness of the channel. Two gates are positioned along the channel, at the opposite walls of vertical structure. The distance between the gates, i.e. width of the channel, is 600 Å. This design configuration demonstrates ability to operate at maximum frequency of about 1 THz. However, with some modification of gates position, the device is capable to operate at 2 – 3 THz. The current gain and S-parameters as well as some fabrication issues are discussed.
Biography: Dr. Samson Mil’shtein is Professor of Electrical and Computer Engineering of UMass Lowell since 1987. During 1998-1999 he served as Assistant Dean of Engineering for Research, UMass Lowell, MA. From 1990 he is the director of the Advanced Electronic Technology Center. His publication list carries over 270 publications, patents, and conference presentations. His current research work covers high speed quantum electronics, solar sell systems, bio-medical engineering. In May 2015 Prof. S. Mil’shtein was elected as Member of Academy (Academician) of Natural Sciences of Kazakhstan Republic.
Abstract: Innovation of Heterojunction Bipolar Transistor (HBT) technology is important in wireless communication (current development of 5G and 6G), power amplifiers and other major fields of electronics. HBTs play a significant role in extending the advantages of silicon bipolar transistors to significantly higher levels. Research on HBT is focused on reducing cost and improving reliability. These transistors have a wide range of applications, namely, digital-to-analog converters, logarithmic amplifiers, RF chip sets for CDMA wireless communication systems, and power amplifiers for cellular communications. Our study focuses on utilizing the high mobility of non-graded Ge instead of often-used graded Ge base of the HBT. This novel design allows to have non-graded Ge base and lattice matching with Si emitter and collector by using two SiGe 20Å-thick buffer layers. Non-graded Ge base enhances carrier transport, which in turn increases the gain and cut-off frequency. Using ATLAS TCAD - SILVACO software we obtained 50GHz cut-off frequency, 35dB current gain, low-noise heterojunction bipolar transistor. Our results indicate that non-graded Ge base could be decreased to the dimensions of quantum well in the HBTs of the future.