Light-induced electron paramagnetic resonance evidence of charge transfer in electrospun fibers containing conjugated polymer/fullerene and conjugated polymer/fullerene/carbon nanotube blends

2012 ◽  
Vol 100 (11) ◽  
pp. 113303 ◽  
Author(s):  
Alexander I. Shames ◽  
Céline Bounioux ◽  
Eugene A. Katz ◽  
Rachel Yerushalmi-Rozen ◽  
Eyal Zussman
2004 ◽  
Vol 59 (12) ◽  
pp. 938-942 ◽  
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong

The electron paramagnetic resonance (EPR) parameters g and the hyperfine structure constants A of Co2+ in ZnX (X = S, Se, Te) and CdTe are studied, using the perturbation formulas of the EPR parameters for a 3d7 ion in tetrahedra based on two mechanism models. In these formulas, both the contributions from the conventional crystal-field (CF) mechanism and those from the charge-transfer (CT) mechanism are taken into account. According to the investigations, the sign of the g-shift ΔgCT from the CT mechanism is the same as ΔgCF from the CF mechanism, whereas the contributions to the A value from the CF and CT mechanisms have opposite signs. Particularly, the contributions to the EPR parameters from the CT mechanism increase rapidly with increase of the spin-orbit coupling coefficient of the ligand and the covalency effect of the systems, i. e. S2− < Se2− < Te2−.


2012 ◽  
Vol 45 (5) ◽  
pp. 972-975
Author(s):  
Lianxuan Zhu ◽  
Minjie Wang

The electron paramagnetic resonance (EPR)g-factor formulas are constructed for ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals based on the contributions of the charge-transfer levels and the spin-orbit coupling effect of the central ion and the ligands. The EPRgfactors are calculated from these formulas, and the calculated values agree well with the experimental ones. The contribution rates of the charge-transfer levels are 10.1, 7.6 and 24.9% for ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals, respectively. Thegfactors obtained from the one-spin-orbit-parameter model are also given for comparison.


2000 ◽  
Vol 633 ◽  
Author(s):  
Marc In Het Panhuis ◽  
Jonathan N. Coleman ◽  
Werner J. Blau

AbstractWe have described a novel experimental technique to separate nanotubes from other unwanted carbon species in arc generated carbon soot. A conjugated polymer was used to bind to nanotubes in solution. The resultant hybrid was soluble while extraneous carbon material formed a sediment at the bottom of the sample bottle. This process was monitored using electron paramagnetic resonance (EPR) which showed that 63% of nanotubes were kept in solution while 98.1% of impurities were rejected. Optimal polymer characteristics for nanotube solubility were identified using geometry optimisation and experimental evidence. It was calculated that a successful polymer has a flat shaped helical backbone with solvent solubilising groups projected outwards. This is achieved with the following polymer characteristics, two solvent solubilising groups on a twist allowing π-conjugated backbone.


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