Porphyrin aggregates in the form of nanofibers and their unusual aggregation induced emission

2012 ◽  
Vol 16 (09) ◽  
pp. 1055-1058 ◽  
Author(s):  
Rakesh K. Pandey ◽  
U. Chitgupi ◽  
V. Lakshminarayanan
Keyword(s):  
Atomic Force Microscopy ◽  
Simple Procedure ◽  
Photoluminescence Spectroscopy ◽  
Emission Property ◽  
Dye Molecules ◽  
Aggregation Induced Emission ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vis Spectroscopy

We present here the simple procedure for synthesizing elongated fibers like porphyrin aggregates. Usually whenever the aggregation in dye molecules takes place the emission always tends to quench. In this work we explore and discuss the unusual enhanced emission property of these aggregates. The nanofibers of porphyrin were characterized with the help of atomic force microscopy and UV-vis spectroscopy whereas photoluminescence spectroscopy was used to check their emission property.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Preparation and Characterization of Electrodes Modified with Metalloporphyrins. Application to Reduction of Nitrite

2003 ◽  
Vol 68 (9) ◽  
pp. 1723-1735 ◽  
Author(s):  
Francisco Armijo ◽  
Ejnar Trollund ◽  
Matías Reina ◽  
M. Carmen Arévalo ◽  
M. Jesús Aguirre
Keyword(s):  
Atomic Force Microscopy ◽  
Cyclic Voltammetry ◽  
Modified Electrodes ◽  
Amino Groups ◽  
Catalytic Behavior ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Hcl Solution

Six type-modified electrodes by electropolymerization of tetrakis(x-aminophenyl)porphyrins, where x = 2, 3 or 4, and their Cu(II) and Ni(II) complexes in HCl solution were prepared and characterized by cyclic voltammetry, atomic force microscopy and UV-VIS spectroscopy. The morphology of the polymers depends on the position of the amino groups. The modified electrodes show interesting electrocatalytic activity toward reduction of nitrites. The catalytic behavior strongly depends on the nature of the metal and the position of the amino groups.

A Study of Exfoliated Molybdenum Disulfide (MoS2) Based on Raman and Photoluminescence Spectroscopy

2018 ◽  
Vol 271 ◽  
pp. 40-46 ◽  
Author(s):  
G. Munkhbayar ◽  
S. Palleschi ◽  
F. Perrozzi ◽  
M. Nardone ◽  
J. Davaasambuu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Molybdenum Disulfide ◽  
Area Ratio ◽  
Photoluminescence Spectroscopy ◽  
Raman Intensity ◽  
Si Substrate ◽  
Force Microscopy ◽  
Atomic Force ◽  
Number Of Layers ◽  
Pl Emission

In this study, We demonstrate mono and few layers MoS2 samples on the SiO2(270nm)/Si substrate from bulk MoS2 crystal by micromechanical exfoliation technique. We have systematically studied Atomic Force Microscopy, Raman and PL properties of mono and few layer MoS2 on the SiO2(270nm)/Si substrate. First, we find that the number of layer values dependent the Raman and PL emission. First, Raman intensity area ratio of the MoS2E12g, A1g and 2LA modes to that area of the Si substrate increased linear with increasing number of layers MoS2. Second, Normalized PL intensity area of the (A) peak decreased linear with increasing number of layers MoS2. The value of those graphs is a method to understand the number of layers the exfoliated MoS2.

scholarly journals Бинарные наносистемы на основе амфифильных молекулярных щеток, загруженных фотосенсибилизатором Радахлорином или наночастицами селена

2020 ◽  
Vol 90 (9) ◽  
pp. 1462
Author(s):  
С.В. Валуева ◽  
Т.Е. Суханова ◽  
М.Э. Вылегжанина ◽  
Т.К. Мелешко
Keyword(s):  
Atomic Force Microscopy ◽  
Main Chain ◽  
Biogenic Element ◽  
Side Chains ◽  
Molecular Brushes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Grafting Density ◽  
Vis Spectroscopy ◽  
Valence Form

The morphological, spectral and molecular conformational characteristics of amphiphilic molecular brushes with polyimide main chain and polymetacrylic acid side chains loaded with a second-generation photosensitizer Radachlorin® or nanoparticles of the biogenic element – selenium in the zero–valence form were studied using atomic force microscopy (AFM), UV-vis spectroscopy and dynamic/static light scattering. The influence of the side chains grafting density of amphiphilic molecular brushes and the hydrophobic preparation/agent loaded into them on the morphological, spectral and molecular conformational characteristics of synthesized binary nanosystems is shown.

Fabrication and Properties of a Nanocomposite Multilayer Film Based on a Polyoxometalate

2012 ◽  
Vol 67 (7) ◽  
pp. 673-677
Author(s):  
Jihong Liu ◽  
Tao Dong ◽  
Shuang Li ◽  
Huiyuan Ma ◽  
Bo Liu
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Multilayer Film ◽  
Color Change ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Assembly Method ◽  
Atomic Force ◽  
Good Electrocatalytic Activity ◽  
Vis Spectroscopy

A nanocomposite multilayer film based on a polyoxometalate Na16[P4W30Mn4 (H2O)2O112]·xH2O (Mn4P4W30) was fabricated by the layer-by-layer self-assembly method. It was characterized by UV/Vis spectra and atomic force microscopy (AFM). The electrochromic and electrocatalytic properties were explored using chronoamperometry (CA), UV/Vis spectroscopy and cyclovoltammetry (CV). The attractable feature is a color change of the film by the reduction of the polyoxometalate at different potentials. The film also exhibits good electrocatalytic activity toward the reduction of IO3-.

Highly soluble tetrasubstituted lanthanide bis-phthalocyanines; synthesis, characterization, electrical properties and aggregation studies

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1065-1074 ◽  
Author(s):  
Ahmet T. Bilgiçli ◽  
Armağan Günsel ◽  
Mehmet Kandaz ◽  
Ahmet Altındal ◽  
Hüseyin Cömert
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Electrical Properties ◽  
Electrical Transport ◽  
Hole Mobility ◽  
Electrical Transport Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Coating Method

We report the synthesis, characterization and electrical properties of lanthanide metal based bis-phthalocyanines, {M[Pc-(β-HHT)4]2} (HHT:1-hydroxyhexane-3-ylthio){ M [Formula: see text] Lu[Formula: see text] (2), Eu[Formula: see text] (3), and Yb[Formula: see text] (4)}. The interaction of bis-phthalocyanines with Ag[Formula: see text] and Pd[Formula: see text] metal ions were investigated by UV-vis spectroscopy and atomic force microscopy. Thin films of bis-phthalocyanine molecules were prepared by spin-coating method. The surface morphology of thin films were performed with Atomic Force Microscopy as further investigate. The electrical transport properties of ITO/Pc/Al devices were investigated. At low voltages all the films showed an ohmic conduction, whereas at higher voltage levels the conduction is dominated by space charged limited conduction with exponential distribution of trapping levels. Measurements of current density as a function of inverse temperature at constant applied voltage yielded a hole mobility values, μp[Formula: see text], [Formula: see text] and [Formula: see text] m2.sn[Formula: see text].V[Formula: see text] for lanthanium phthalocyanines. From the analysis of frequency, ω, dependence of electrical conductivity, σac. it was found that the [Formula: see text] obeys the power law given by σac = Aωs, in which the frequency exponent “s” decreases with temperature.

scholarly journals Controlling of optical band gap of the CdO films by zinc oxide

2019 ◽  
Vol 37 (1) ◽  
pp. 136-141
Author(s):  
Nida Kati
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Structure ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Zno Film ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdo Films

AbstractIn this study, CdZnO films prepared at different ratios of dopants (CdO:ZnO = 5:5, CdO:ZnO = 6:4, and CdO:ZnO = 8:2) were coated on glass surface by using the sol-gel spin coating technique. After this process, surface structure and optical properties of the CdZnO films was investigated by atomic force microscopy (AFM) and UV-Vis spectroscopy. The surface structure of the CdZnO films depended on the content of ZnO and CdO in the films. Low percentage of CdO films were very similar to the ZnO film but higher amount of CdO resuted in granular structures together with pure structure of ZnO in the films. Eg values of produced CdZnOs depended on the additions of CdO and ZnO. The obtained Eg values of the produced CdO:ZnO = 5:5 (S3), CdO:ZnO = 6:4 (S4), and CdO:ZnO = 8:2 (S5) films are 2.5 eV, 2.49 eV, and 2.4 eV, respectively.

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