Solvation-induced line-width alternation in the electron spin resonance spectra of the meta-dinitrobenzene anion and of various symmetrically substituted dinitro-compounds in the benzene and naphthalene series

1970 ◽  
pp. 1261 ◽  
Author(s):  
C. J. W. Gutch ◽  
W. A. Waters ◽  
M. C. R. Symons
Keyword(s):  
Electron Spin Resonance ◽  
Line Width ◽  
Electron Spin ◽  
Spin Resonance ◽  
Naphthalene Series

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.

An electron spin resonance study of pure anthracene doped with alkali metals

1970 ◽  
Vol 23 (2) ◽  
pp. 261 ◽  
Author(s):  
VC Bien ◽  
LE Lyons
Keyword(s):  
Electron Spin Resonance ◽  
Alkali Metal ◽  
Exchange Interaction ◽  
Line Width ◽  
Electron Spin ◽  
Alkali Metals ◽  
Spin Lattice Relaxation ◽  
Electron Spin Resonance Study ◽  
Pure Nitrogen ◽  
Spin Resonance

When pure anthracene is melted under a pure nitrogen atmosphere in the presence of an alkali metal, the metal dissolves forming a blue-green melt which exhibits an electron spin resonance (e.s.r.) signal. The polycrystalline samples of the solid system (MAn) obtained by cooling the melt also exhibit e.s.r, signals but with a line-width greater than that seen in the melt. The Lorentzian line-shapes in the solid and the melt indicate that the electrons producing the signals are either delocalized, or clustered and undergoing exchange interaction. The following features are discussed: the lack of hyperfine structure in the melt except for a special case; the Curie dependence of the susceptibility; the dependence of the g-values on the alkali metal; the shifts of the g-values on melting the samples; the behaviour of the line-width with respect to deuteration of anthraoene and with respect to the different alkali metals; and the dependence of the spin-lattice relaxation time on the alkali metal and on whether the sample was solid or molten. The features indicate that the electrons behave as simple doublets, are clustered with the alkali-metal complex in the solid and undergo exchange interaction, produce motional narrowing of lines in the melt, and produce a line-width mainly dependent on the alkali metal ions in the solid and to a lesser extent in the melt.

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