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Structural and electrical properties of new core-shell silver poly(m-toluidine-co-2-bromoaniline) nanocomposites

Mahudeswaran A., Jeeva A., Chandrasekaran J., Vijayanand P. S.

Materials Science Poland

2019

Vol. 37, No. 4

526--534

In this article, we report the synthesis and characterization of silver dispersed poly(m-toluidine-co-2-bromoaniline) copolymer synthesized by chemical oxidative polymerization method. The synthesized copolymer composites were subjected to different analytical characterization methods, such as FT-IR, UV, XRD, SEM, photoluminescence and electrical conductivity studies. All the polymer samples are found to be soluble in common organic solvents. UV absorption spectra show a red shift when silver nanoparticles are dispersed in the copolymer. The characteristic peaks observed in FT-IR spectra confirm the formation of the copolymer. XRD pattern reveals the crystalline nature of the copolymer composites and sharp peaks in the spectra confirm the presence of silver particles. The silver nanoparticles change the surface morphology in the form of perfect encapsulation. The electrical conductivity of the polymer composites is found to vary from 10-4 S/cm to 10-6 S/cm. PL study reveals the charge transfer between the copolymer and the silver particles.

Investigation on photoluminescence quenching of CdSe/ZnS quantum dots by organic charge transporting materials

Qu Y., Zhang L., An L., Wei H.

Materials Science Poland

2015

Vol. 33, No. 4

709--713

The effect of different organic charge transporting materials on the photoluminescence of CdSe/ZnS core/shell quantum dots has been studied by means of steady-state and time-resolved photoluminescence spectroscopy. With an increase in concentration of the organic charge transporting material in the quantum dots solutions, the photoluminescence intensity of CdSe/ZnS quantum dots was quenched greatly and the fluorescence lifetime was shortened gradually. The quenching efficiency of CdSe/ZnS core/shell quantum dots decreased with increasing the oxidation potential of organic charge transporting materials. Based on the analysis, two pathways in the photoluminescence quenching process have been defined: static quenching and dynamic quenching. The dynamic quenching is correlated with hole transporting from quantum dots to the charge transporting materials.

Highly efficient organic ultraviolet photodetectors based on excellent Cu(I) complexes

Liu C. B., Su B., Liu M., Zhang X. X., Wang L., Zhang S., Che G. B., Xu Z. L.

Opto-Electronics Review

2013

Vol. 21, No. 3

288-292

We demonstrate high response organic ultraviolet photodetectors using 4,4',4''-tris[3-methyl-pheny(phenyl)amino]tri-phenylamine (m-MTDATA) and two novel Cu(I) complexes, [Cu(DPEphos)(PyPhen)]BF (CuDP)(DPEphos = Bis [2-(diphenylphosphino)phenyl]ether, PyPhen = pyrazino[2,3-f][1,10]phenanthroline) and [Cu(DPEbenz)(PyPhen)] BF₄(CuBP) (DPEbenz = 1,2-bis(diphenylphosphino)benzene) to act as the electron donor and acceptor, respectively. Strong photoluminescence quenching of m-MTDATA by Cu(I) complexes is observed manifesting the efficient photoinduced charge transfer that occurs between m-MTDATA and Cu(I) complexes. The optimized photodetector based on CuBP exhibits a maxi-mum response of 276 mA/W at -12 V under an illumination of 365 nm UV light irradiation with an intensity of 1.75 mW/cm². The high response is attributed to feasible energy level match, efficient electron transfer from m-MTDATA to CuBP and skillful device design. More detailed working mechanism of harvesting high performance is also discussed.