A Study of Cation-exchange Reactions in the System Potassium Durosemiquinone – Potassium Tetraphenylboride – Tetrahydrofuran

1971 ◽  
Vol 49 (9) ◽  
pp. 1529-1538 ◽  
Author(s):  
T. E. Gough ◽  
P. R. Hindle
Keyword(s):  
Electron Spin Resonance ◽  
Spectral Line ◽  
Cation Exchange ◽  
Line Width ◽  
Electron Spin ◽  
Potassium Ion ◽  
Exchange Reactions ◽  
Line Shapes ◽  
Intramolecular Exchange ◽  
Spin Resonance

The electron spin resonance (e.s.r.) spectrum of potassium durosemiquinone in tetrahydrofuran has been studied as a function of temperature and found to exhibit line-width alternation indicating the presence of an intramolecular migration of the potassium ion between the oxygens of the semiquinone. The addition of potassium tetraphenylboride to the system produces intermolecular scrambling of potassium, the spectral effects of which are superimposed upon those of the intramolecular exchange. From the spectral line-shapes approximate values of the activation energies and frequency factors were derived. The tetraphenylboride anion did not play a detectable role in the various exchange mechanisms.

Electron Spin Resonance Investigations on Perovskite Solar Cell Materials Deposited on Glass Substrate

MRS Advances ◽  
2018 ◽  
Vol 3 (32) ◽  
pp. 1831-1836
Author(s):  
C. L. Saiz ◽  
E. Castro ◽  
L. M. Martinez ◽  
S. R. J. Hennadige ◽  
L. Echegoyen ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Solar Cell ◽  
Line Width ◽  
Electron Spin ◽  
Glass Substrate ◽  
Esr Spectra ◽  
Perovskite Solar Cell ◽  
Hole Transport ◽  
Ex Situ ◽  
Spin Resonance

ABSRTACTIn this article, we report low-temperature electron spin resonance (ESR) investigations carried out on solution processed three-layer inverted solar cell structures: PC61BM/CH3NH3PbI3/PEDOT:PSS/Glass, where PC61BM and PEDOT:PSS act as electron and hole transport layers, respectively. ESR measurements were conducted on ex-situ light (1 Sun) illuminated samples. We find two distinct ESR spectra. First ESR spectra resembles a typical powder pattern, associated with gx = gy = 4.2; gz = 9.2, found to be originated from Fe3+ extrinsic impurity located in the glass substrate. Second ESR spectra contains a broad (peak-to-peak line width ∼ 10 G) and intense ESR signal appearing at g = 2.008; and a weak, partly overlapped, but much narrower (peak-to-peak line width ∼ 4 G) ESR signal at g = 2.0022. Both sets of ESR spectra degrade in intensity upon light illumination. The latter two signals were found to stem from light-induced silicon dangling bonds and oxygen vacancies, respectively. Our controlled measurements confirm that these centers were generated during UV-ozone treatment of the glass substrate –a necessary step to be performed before PEDOT:PSS is spin coated. This work forms a significant step in understanding the light-induced- as well as extrinsic defects in perovskite solar cell materials.

Electron spin resonance spectra of nitric oxide adsorbed on zeolites

1970 ◽  
Vol 48 (8) ◽  
pp. 1317-1322 ◽  
Author(s):  
C. L. Gardner ◽  
M. A. Weinberger
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Iterative Procedure ◽  
Axial Component ◽  
Axially Symmetric ◽  
Electric Field Gradients ◽  
Line Shapes ◽  
Field Gradients ◽  
Spin Resonance ◽  
Surface Fields

Electron spin resonance (e.s.r.) spectra of NO adsorbed on the 4 zeolites Linde 4A, 5A, 13X, and hydrogen mordenite were measured at 77°K. No e.s.r. signal was observed for NO on silica gel. By use of expressions for the line shapes of polycrystalline samples, assuming axially symmetric g-tensors, and taking into account also isotropic coupling, values of [Formula: see text] and line width were derived by an iterative procedure. From these, the crystal field splitting, Δ, of the 2pπ levels, which become non-degenerate on adsorption, were calculated. By relating Δ to the interaction of the non-axial components of the quadru-pole moment with the corresponding electric field gradients, the non-axial component of the latter is estimated for the surface fields of the zeolites.

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