scholarly journals Multi-Conformational Luminescence and Phosphorescence of Few Phenazine 1,2,3-Triazole Molecules

2022 ◽  
Author(s):  
Pablo B. Pinto ◽  
Kimberly C. T. da Cruz ◽  
Eufrânio Nunes da Silva Júnior ◽  
Luiz Alberto Cury
Keyword(s):  
Incident Laser ◽  
Guest Molecules ◽  
Emission Properties ◽  
Blend Films ◽  
Inert Matrix ◽  
Active Layers ◽  
Singlet States ◽  
Low Concentrations ◽  
Conductive Properties ◽  
Exponentially Modified Gaussian

Abstract Dropcast films produced from blends solutions of phenazine 1,2,3-triazole molecules in very low concentrations in a 1,3-Bis (N-carbazolyl) benzene (mCP) matrix were investigated at room temperature. The mCP acts as an optically inert matrix, having no influence on the emission properties of the guest molecules. Its conductive properties also ensure that blend films, within a completely organic character, are formed as truly active layers. The fluorescent and phosphorescent emission properties of the phenazine molecules, depending on their conformational states, allowed relatively intense emissions in blue, green, red and also in white, without the need to mix different materials. Although the results of absorption of the blended films have shown no characteristics of the guest molecules, due to their relatively low concentrations, the excitation of them occurs directly by the incident laser beam. The steady-state spectroscopy for the monomer and dimer singlet fluorescence states of respective blue and green emissions of the films were investigated. The analysis of their temporal decays were done using a different approach based on the Exponentially Modified Gaussian (EMG) function. The phosphorescent emissions of the triplet steady-states, occurring in the orange or in the red wavelength regions, were observed to be correlated, respectively, to the formation of guest monomers or to the guest dimers singlet states.

Effects of Oxygen in CaS:Eu Active Layers on Emission Properties of Thin Film Electroluminescent Cells

1990 ◽  
Vol 29 (Part 1, No. 8) ◽  
pp. 1495-1498 ◽  
Author(s):  
Yoshio Abe ◽  
Ken-ichi Onisawa ◽  
Yoshimasa A. Ono ◽  
Masanobu Hanazono
Keyword(s):  
Thin Film ◽  
Emission Properties ◽  
Active Layers

Novel dithienopyrrole-based molecular donor materials for organic solar cells

2017 ◽  
Vol 10 (06) ◽  
pp. 1750085 ◽  
Author(s):  
Zong-Bing Zhang ◽  
Jia-Wei Xu ◽  
Xin-Yu Zhang ◽  
Shi-Xin Sun ◽  
Rong Xing
Keyword(s):  
Thermal Stability ◽  
Organic Solar Cells ◽  
Energy Levels ◽  
Visible Region ◽  
Solvent Vapor ◽  
Excellent Thermal Stability ◽  
Blend Films ◽  
Absorption Energy ◽  
Active Layers ◽  
Solvent Vapor Annealing

A new molecule with dithieno[3,2-b:2’,3’-d]pyrrole (DTP) as central moiety and two terminal diketopyrrolopyrrole (DPP) units named DPP-DTPC8 has been designed and synthesized. The push–pull molecule exhibits excellent thermal stability, strong absorption in visible region, and matched energy levels. Devices fabricated from DTPC8:PC[Formula: see text]BM blend films exhibit the maximum power conversion efficiency of 2.75%, with Voc of 0.63 V, Jsc of 9.94 mA[Formula: see text] cm[Formula: see text], and FF of 43.8%. The active layers undergo thermal annealing or solvent vapor annealing treatments, exhibiting inconspicuous influence on the aggregation of the molecule. This study demonstrates that the new molecule DPP-DTPC8 tailored with DTP and DPP units could affect the thermal stability, absorption, energy levels and morphology that manage the photovoltaic performances.

scholarly journals Axial Orientation of Co-Crystalline Phases of Poly(2,6-Dimethyl-1,4-Phenylene)Oxide Films

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2394
Author(s):  
Manohar Golla ◽  
Baku Nagendra ◽  
Christophe Daniel ◽  
Paola Rizzo ◽  
Gaetano Guerra
Keyword(s):  
Relevant Information ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Blend Films ◽  
Crystalline Polymers ◽  
Temperature Range ◽  
Plasticization Effect ◽  
Phenylene Oxide ◽  
Polymer Oxidation

Films exhibiting co-crystalline (CC) phases between a polymer host and low-molecular-mass guest molecules are relevant for many applications. As is usual for semi-crystalline polymers, axially oriented films can give relevant information on the crystalline structure, both by Wide Angle X-ray diffraction fiber patterns and by polarized Fourier-transform infrared spectroscopy. Axially oriented CC phases of poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) with 1,3,5-trimethylbenzene (mesitylene) can be simply obtained by the stretching of CC PPO films. In fact, due to the plasticization effect of this highly boiling guest, PPO orientation can occur in a stretching temperature range (170–175 °C) nearly 50 °C lower than that generally needed for PPO films (220–230 °C). This low stretching temperature range allows avoidance of polymer oxidation, as well as formation of the mesomorphic dense γ PPO phase. Axially oriented CC phases of PPO with toluene, i.e., with a more volatile guest, can be instead obtained by the stretching (in the same low temperature range: 170–175 °C) of CC PPO blend films with polystyrene.

Excitation and Emission Properties of Platinum(II) Acetylides at High and Low Concentrations

2009 ◽  
Vol 113 (42) ◽  
pp. 11242-11249 ◽  
Author(s):  
Eirik Glimsdal ◽  
Patrick Norman ◽  
Mikael Lindgren
Keyword(s):  
Emission Properties ◽  
Low Concentrations

Der Konzentrationsumschlag der Fluoreszenz aromatischer Kohlenwasserstoffe in mizell-kolloidaler Lösung

1964 ◽  
Vol 19 (1) ◽  
pp. 38-41 ◽  
Author(s):  
Th. Förster ◽  
B. Selinger
Keyword(s):  
Aqueous Solution ◽  
Fluorescence Spectra ◽  
Excited Singlet ◽  
Concentration Effects ◽  
Dimer Formation ◽  
Singlet States ◽  
Low Concentrations ◽  
Excited Singlet States ◽  
Methyl Naphthalene ◽  
Monomer Fluorescence

Concentration effects in fluorescence spectra, resulting from transient dimer formation in excited singlet states, have been studied in the presence of a detergent in aqueous solution. 2-methyl-naphthalene and pyrene have been used as fluorescers, and cetyl-dimethyl-benzylammonium-chloride as the detergent. The intensity ratio of dimer to monomer fluorescence components has been measured for dilution of the fluorescer alone and also of fluorescer and detergent. The results show that with 2-methyl-naphthalene transient dimer formation depends on the fluorescer concentration within the micelles. With pyrene, where dimer formation occurs at very low concentrations, it seems to depend on the number of single fluorescer molecules per micelle.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

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