scholarly journals Novel Solid-State Emissive Polymers and Polymeric Blends from a T-Shaped Benzodifuran Scaffold: A Comparative Study

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 718
Author(s):  
Ugo Caruso ◽  
Rosita Diana ◽  
Angela Tuzi ◽  
Barbara Panunzi

Two novel polyimines were synthesized from a benzodifuran based diamino monomer and two dialdehydes bearing bulky groups and a flexible spacer. The polymers display tuned luminescence performance according to the presence of half-salen groups. The effect of the intramolecular bond on the emission properties were examined. Two model compounds, replicating the same emissive Schiff base cores, were synthetized. From the models, dye-doped blends in the fluorophore/matrix ratio, resembling the polymers, were produced. Amorphous thin films of the covalent polymers and the polymeric blends were obtained by spin-coating technique. The Photoluminescent (PL) response of the different macromolecular systems were qualitatively and quantitatively examined and compared.

2013 ◽  
Vol 667 ◽  
pp. 317-323 ◽  
Author(s):  
Muhamad Nur Amalina ◽  
Mohamad Rusop

The improvement of solid-state dye sensitized solar cells requires identification and understanding of hole transport material properties at various deposition process that limit the energy conversion efficiency. A well-studied of this hole collectors properties, a high efficiency ss-DSSC is highly achievable. In this research work, the copper (I) iodide (CuI) had been deposited by spin coating and mist-atomization technique. The thin films characteristics of surface morphology and electrical properties and its effect to the photovoltaic performance were investigated. The thin films morphology examined by FESEM shows smaller CuI crystal size deposited by spin coating (S1) of ~30nm. Even though, smaller particle size of hole conductor is desirable in order to achieve high pore penetration, the thin film thickness and the electrical resistivity are also essential. The CuI thin films deposited by mist-atomization (M1) shows a low resistivity of 1.77 x 10-1 Ωcm which will greatly affect the device performance. The photovoltaic performance of ss-DSSC at different method CuI deposition shows the highest efficiency of 1.05% for sample (M1) while the ss-DSSC fabricated with S1 sample shows the lowest conversion efficiency of 0.02%. The appropriate crystals size of CuI, film thickness and the electrical resistivity greatly contributed to the high filling fraction of the porous TiO2 layer and hence the cells performance.


2016 ◽  
Vol 698 ◽  
pp. 60-65 ◽  
Author(s):  
Tôru Kyômen ◽  
Miyu Seki ◽  
Minoru Hanaya ◽  
Hiroshi Takashima

Powder samples of (Ca,Sr)TiO3:Er were prepared by a solid-state reaction method. Photoluminescence due to f-f transitions of Er3+ was not induced by band-gap excitation of (Ca,Sr)TiO3 but by f-f transitions of Er3+. An electroluminescent device in which thin films of Ca0.6Sr0.4TiO3:Er and SnO2:Sb are stacked alternately was prepared by sol-gel and spin-coating methods. Very weak electroluminescence due to f-f transition of Er3+ was observed in the device.


RSC Advances ◽  
2018 ◽  
Vol 8 (51) ◽  
pp. 29096-29103 ◽  
Author(s):  
Laila Almanqur ◽  
Inigo Vitorica-yrezabal ◽  
George Whitehead ◽  
David J. Lewis ◽  
Paul O'Brien

Iron(iii) xanthate single-source precursors were used to deposit iron sulfide thin films and nanostructures by spin coating and solid state deposition.


2019 ◽  
Vol 948 ◽  
pp. 287-293
Author(s):  
Mulya Supianto ◽  
Suyanta Suyanta ◽  
Indriana Kartini

Methylammonium lead trihalide perovskites have emerged as attractive materials for solar cell applications. The major eminence of this materials can be crystallized via various solution methods to produce the solid state of thin films. However, the crystallinity of perovskite depends on the composition of perovskites. Here, we study NH4Cl and NH4Br as precursor additives for improving crystallinity of perovskites. Perovskite was synthesized by mixing precursor solutions of CH3NH3I and Pb(Ac)2with or without additives NH4Cl and NH4Br using the one-step spin-coating method. By characterizing the thin films using XRD, SEM and UV-Vis spectrophotometer, we found anion Cl and Br performed an important role toward crystallinity, morphology, and optical absorption of perovskites, respectively. Meanwhile, ammonium has assisted to facile remove the residual DMSO solvent confirmed by FTIR. These results shed light on using ammonium halides as potentially dual side additives in the synthesis of perovskites.


2010 ◽  
Vol 71 (9) ◽  
pp. 1367-1372 ◽  
Author(s):  
G. Cabello ◽  
L. Lillo ◽  
C. Caro ◽  
B. Chornik ◽  
M.A. Soto ◽  
...  

Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.


2019 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
KOMARAIAH DURGAM ◽  
RADHA EPPA ◽  
REDDY M. V. RAMANA ◽  
KUMAR J. SIVA ◽  
R. SAYANNA ◽  
...  

2019 ◽  
Vol 15 (8) ◽  
pp. 850-862
Author(s):  
Mirthala Flores-García ◽  
Juan Manuel Fernández-G. ◽  
Cristina Busqueta-Griera ◽  
Elizabeth Gómez ◽  
Simón Hernández-Ortega ◽  
...  

Background: Ischemic heart disease, cerebrovascular accident, and venous thromboembolism have the presence of a thrombotic event in common and represent the most common causes of death within the population. Objective: Since Schiff base copper(II) complexes are able to interact with polyphosphates (PolyP), a procoagulant and potentially prothrombotic platelet agent, we investigated the antiplatelet aggregating properties of two novel tridentate Schiff base ligands and their corresponding copper( II) complexes. Methods: The Schiff base ligands (L1) and (L2), as well as their corresponding copper(II) complexes (C1) and (C2), were synthesized and characterized by chemical analysis, X-ray diffraction, mass spectrometry, and UV-Visible, IR and far IR spectroscopy. In addition, EPR studies were carried out for (C1) and (C2), while (L1) and (L2) were further analyzed by 1H and 13C NMR. Tests for antiplatelet aggregation activities of all of the four compounds were conducted. Results: X-ray diffraction studies show that (L1) and (L2) exist in the enol-imine tautomeric form with a strong intramolecular hydrogen bond. NMR studies show that both ligands are found as enol-imine tautomers in CDCl3 solution. In the solid state, the geometry around the copper(II) ion in both (C1) and (C2) is square planar. EPR spectra suggest that the geometry of the complexes is similar to that observed in the solid state by X-ray crystallography. Compound (C2) exhibited the strongest antiplatelet aggregation activity. Conclusion: Schiff base copper(II) complexes, which are attracting increasing interest, could represent a new approach to treat thrombosis by blocking the activity of PolyP with a potential anticoagulant activity and, most importantly, demonstrating no adverse bleeding events.


Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.


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