Search query: OPTICAL PROPERTIES AND SPECTROSCOPY OF NANOMATERIALS

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abstract: Optical properties are among the most fascinating and useful properties of nanomaterials and have been extensively studied using a variety of optical spectroscopic techniques. A basic understanding of the optical properties and related spectroscopic techniques is essential for anyone who is interested in learning about nanomaterials of semiconductors, insulators or metal. This is partly because optical properties are intimately related to other properties and functionalities (e.g. electronic, magnetic, and thermal) that are of fundamental importance to many technological applications, such as energy conversion, chemical analysis, biomedicine, optoelectronics, communication, and radiation detection. Intentionally designed for upper level undergraduate students and beginning graduate students with some basic knowledge of quantum mechanics, this book provides the first systematic coverage of optical properties and spectroscopic techniques of nanomaterials.
author_names: Jin Z Zhang
title: Optical Properties And Spectroscopy Of Nanomaterials
year: 2009

author_names: Andre J Gesquiere
title: Optical Properties and Spectroscopy of Nanomaterials
year: 2010

author_names: Raul Jose Martin-Palma
title: Book Review: Optical Properties and Spectroscopy of Nanomaterials
year: 2009

abstract: Abstract Doping of materials by suitable additives can dramatically modify the physical characteristics of the complex systems. In this paper, we investigate the role of gadolinium concentration on the linear, nonlinear optical properties and transient absorption dynamics of ZnO and Al doped ZnO. The characteristics of the mentioned materials with different dopant concentrations are evaluated using absorption spectroscopy, Z scan and pump probe technique with femtosecond laser pulses at 800 and 400 nm wavelengths. The nonlinear absorption is increased in Al doped ZnO compared to pure ZnO at 800 nm wavelength. Gadolinium dopant demonstrated a significant reduction in nonlinear refractive index and absorption of Al doped ZnO but could not influence pure ZnO. The transient absorption dynamics of ZnO and Al doped ZnO illustrated the decrease of response time with dopant concentration. We also generated high order harmonics using nanosecond heating pulses to generate laser plasmas and femtosecond driving pulses propagating through the plasmas. Laser plasma was generated from an ablated Gd doped ZnO and the high order harmonics were studied by varying the delay between heating and driving pulses.
author_names: Mottamchetty Venkatesh

Rashid A Ganeev

Konda Srinivasa Rao

Ganjaboy S Boltaev

Ke-Xin Zhang

Amit Kumar Srivastava

Jasleen K Bindra

Subhash C Singh

Vyacheslav V Kim

Sandeep Maurya

Geoffrey F Strouse

Naresh S Dalal

Chunlei Guo
title: Influence of gadolinium doping on low and high order nonlinear optical properties and transient absorption dynamics of ZnO nanomaterials
venue: Optical Materials
year: 2019

abstract: Author(s) Joshi, Trinity Advisor(s) Crommie, Michael F Abstract: This dissertation is divided into two segments. The first segment focuses on the structural and electronic characterization of one dimensional (1D) and two dimensional (2D) nanostructures using scanning tunneling microscopy (STM) and spectroscopy (STS) The second segment focuses on the investigation of unique optical behavior in 1D 2D heterosystems using scattering scanning near field optical microscopy (s SNOM).Bottom up synthesis from molecular precursors provides a useful methodology for designing and fabricating interesting nanomaterials. The first part describes application of bottom up synthesis techniques to fabricate 1D nanostructures (graphene nanoribbons (GNRs) and 2D networks (covalent organic frameworks (COF) Following the synthesis, the structural and electronic properties of these nanomaterials were studied using STM and STS. In this dissertation, two specific GNR projects are discussed that provide in detail investigation of the manipulation of the electronic properties of GNRs through the site specific introduction of dopant atoms. The first project describes the detailed study of boron doped N=7 AGNRs, where the AGNRs are substitutionally doped with boron atoms in their backbone. The second project focuses on the study of sulfur doped N=13 GNRs, where the sulfur atoms substitutionally dope the edges of the GNRs. This dissertation also describes two COF projects that demonstrate the strong dependence of the electronic structure of single layer COFs on the chemical bond arrangement within the covalent network. Specifically, the synthesis and characterization of two different porphyrin based single layer 2D COFs that exhibit symmetric (COF 366 OMe) and asymmetric (COF 420) bonding environments are studied. The second part of the thesis describes investigation of the coupling between 1D plasmon polaritons in silver nanowires with 2D phonon polaritons of the silicon carbide (SiC) substrate. The silver nanowire SiC hybrid structure was investigated using near field infrared spectroscopy. A significant change in the 1D plasmon dispersion by the 2D phonon polaritons in SiC was observed upon approaching the SiC phonon polariton energies.
author_names: Trinity Joshi
title: Local Probe Analysis of the Structural, Electronic, and Optical Properties of Nanomaterials
year: 2019

abstract: Nanostructured NiSb2O6 samples were synthesized via solid state reactions at the reaction temperatures of 600, 700 and 800 degC using Sb2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O as raw materials. Parameters of reaction temperature and raw materials types were investigated for the crystal phase growth study. The synthesized nanomaterials were characterized by X ray powder diffraction (XRPD) technique, fourier transform infrared (FTIR) spectroscopy. Brunauer Emmett Teller (BET) and Barrett Joyner Halenda (BJH) methods were used to investigate the textural properties of the obtained samples. Rietveld analyses showed that the obtained materials were crystallized well in the tetragonal crystal structure with the space group of P42/mnm. The lattice parameters of the targets were about a b 4.64 A and c 9.22 A. The data revealed that the crystal phase purity of the as synthesized nanomaterials was increased with increasing the reaction temperature from 600 to 800 degC. Besides, the data indicated that the synthesis reactions using Ni(NO3)2.6H2O generated a better crystalline growth and purity compared to Ni(CH3COO)2.2H2O raw material in a certain reaction temperature. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM) technique. The FESEM images showed that the homogeneity of the synthesized powder was improved when Ni(NO3)2.6H2O was used as raw material. Ultraviolet visible spectra showed that the synthesized NiSb2O6 nanomaterials had strong light absorption in the ultraviolet light region. The calculated direct optical band gaps tendency showed that the band gaps were increased with increasing the reaction temperature.
author_names: Alireza Hakimyfard
title: Effects of reaction temperature and raw material type on optical properties and crystal phase growth of Solid state synthesized NiSb2O6 nanomaterials
year: 2018

abstract: Abstract N doped TiO2 nanomaterials were prepared by wet chemical method. X ray diffraction patterns confirm formation of TiO2 with anatase phase. The SEM images show formation of cubical and porous morphology. UV VIS spectroscopy and Diffuse reflectance spectroscopy confirms band gap of TiO2 nanomaterial lies within the range ~3.0 eV) as reported by earlier researchers. The prepared samples tested for dye degradation application. The results of photocatalytic activities shows that better photocatalytic activity of N doping than undoped TiO2.
author_names: Pragati S Jadhav

Tejaswini Jadhav

Mohini Bhosale

C H Jadhav

Varsha Pawar
title: Structural and optical properties of N doped TiO2 nanomaterials
year: 2020

abstract: The effect of surface structure on the optical and electronic properties of nanomaterials Trevor D. Hull Surface passivation of semiconductor quantum dots is essential to preserve their efficient and robust light emitting properties. By using a lattice matched (mismatch 0.5% lead halide perovskite matrix, we achieve shell like passivation of lead sulfide QDs in crystalline films, leading to efficient infrared light emission. These structures are made from a simple one step spin coating process of an electrostatically stabilized colloidal suspension. Photoluminescence and transient absorption spectroscopy indicate rapid energy transfer between the perovskite matrix and the QDs, suggesting an interface with few trap states. In addition to housing the efficient infrared QD emitters, lead halide perovskites themselves have good carrier mobilities and low trap densities, making these solution processable heterostructures an attractive option for electrically pumped light emitting devices. The highest performing quantum dots for visible light applications are CdE (E=chalcogenide) core/shell heterostructures. Again, surface passivation plays a huge role in determining the brightness and robustness of visible QD emitters. Multilayer shell passivation is usually used to produce the highest quantum yield particles. Surface trap states are shown to be detrimental to luminescence output, even in thick shelled particles. Spherical quantum wells allow for thicker shells and with good surface passivation, show promising reduction of biexciton auger recombination, as measured by a time correlated single photon counting (TCSPC) microscope. TCSPC methods were used to diagnose and identify QD architectures for LED applications and explore fundamental recombination dynamics using photon antibunching measurements, and statistical analysis of blinking traces. Introducing new surfaces onto graphitic substrates can be a useful for introducing new electronic properties, patterning device specific geometries, or appending molecular catalysts. Metal nanoparticles were used to act as a catalyst for the gasification and etching of graphite and graphene. Several methods of controlling the initiation, propagation, and density of these trenches were explored. Patterning defects helped control where initiation occurred, while faceting existing defect sites could also enable more facile initiation and control the direction at the beginning of etching, due to the wetting mechanism of particle movement. Patterning the metal also was shown as a promising avenue to limit unwanted gasification and promote etching in specific, patterned regions. Surface functionalization using reactive gases was performed and characterized with outlook for future experiments.
author_names: Trevor D Hull
title: The effect of surface structure on the optical and electronic properties of nanomaterials
year: 2019

abstract: Abstract Nanomaterials (NMs) are an important part of nanoscience and nanotechnology, which became not only an important and active area of research, but also an economic sector in full expansion in many application domains. The enhancement of useful properties (e.g. self healing, self cleaning, anti freezing, and antibacterial) are the result of careful investigation of the produced NMs. An accurate and precise characterization of NMs with regard to the intended application is important. Characterization techniques have been developed as faster than nanosciences and nanotechnology, but they will continue improving. Actually, characterization techniques not only provide images, but also can also provide fundamental information regarding the composition and properties of NMs all the way down to the atoms. This chapter presents information about dynamic light scattering (DLS) Brunauer Emmett Teller (BET) surface area, ultraviolet visible (UV vis) spectroscopy, photoluminescence spectroscopy (PLS) fluorescence spectroscopy (FS) dielectric spectroscopy (DS) and magnetic measurements, along with brief description of strengths and limitations of each technique, is discussed.
author_names: Ahmed Barhoum

Maria Luisa Garcia-Betancourt
title: Physicochemical characterization of nanomaterials: size, morphology, optical, magnetic, and electrical properties
year: 2018

abstract: Tremendous progress in nanotechnology has enabled advances in the use of luminescent nanomaterials in imaging, sensing and photonic devices. This translational process relies on controlling the photophysical properties of the building block, that is, single luminescent nanoparticles. In this Review, we highlight the importance of single particle spectroscopy in revealing the diverse optical properties and functionalities of nanomaterials, and compare it with ensemble fluorescence spectroscopy. The information provided by this technique has guided materials science in tailoring the synthesis of nanomaterials to achieve optical uniformity and to develop novel applications. We discuss the opportunities and challenges that arise from pushing the resolution limit, integrating measurement and manipulation modalities, and establishing the relationship between the structure and functionality of single nanoparticles. Single particle spectroscopic techniques that provide insights into the fundamental photophysical properties of functional nanomaterials are reviewed.
author_names: Jiajia Zhou

Alexey I Chizhik

Steven Chu

Dayong Jin
title: Single particle spectroscopy for functional nanomaterials
venue: Nature
year: 2020