Role of recombination, dissociation, and competition between exciton-charge reactions in magnetoconductance of polymeric semiconductor device

Journal Article · Fri Nov 14 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4901506· OSTI ID:22402626

Saidani, M. A.; Ben Fredj, A.; Bouchriha, H. ^[1]; Romdhane, S. ^[1]; Havlicek, M.; Egbe, D. A. M.; Sariciftci, N. S. ^[2]

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1. Laboratoire Matériaux Avancés et Phénomènes Quantiques, Faculté des Sciences de Tunis, Université El Manar, 2092 Campus Universitaire, Tunis (Tunisia)
2. Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz (Austria)

Magnetoelectrical measurements were performed on a diode structure, based on an anthracene-containing poly(arylene-ethynylylene)-alt-poly(arylene-vinylene) denoted AnE-PVstat, to clarify the role of the recombination and dissociation of electron-hole (e-h) pairs in the magnetoconductance (MC). We report the observed MC under a weak magnetic field (<1 T) at room and low temperatures. Positive MC is observed and reaches up to 2% at a magnetic field of 450 mT at room temperature. It is found that with the increase of the voltage, the MC effect decreases. We also report the difference in MC between perpendicular (θ = 90°) and parallel (θ = 0°) alignment of magnetic field with respect to the current direction. The experimental data were analyzed in the context of the e-h pair model, based on the Stochastic Liouville Equation. To interpret the experimental results on magnetoconductance measurements, anisotropic hyperfine interaction has been introduced through an anisotropic hyperfine field. The dissociation rates q{sub S} and q{sub T} of the singlet and triplet e-h pairs were determined from the best fit with experimental curves and are about 10{sup 5 }s{sup −1}, while the recombination rates of the singlet and triplet e-h pairs are k{sub S} ∼ 10{sup 9 }s{sup −1} and k{sub T} ∼ 10{sup 5 }s{sup −1}, respectively. At low temperatures (T < 60 K), an unexpected “sign-reversal phenomenon” of the magnetoconductance is observed.

• OSTI ID: 22402626
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
ANTHRACENE
BOLTZMANN-VLASOV EQUATION
DISSOCIATION
MAGNETIC FIELDS
RECOMBINATION
SEMICONDUCTOR DEVICES
T QUARKS
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0273-0400 K
TRIPLETS