The tunable role of electron-hole pair dissociation rate on the magnetic field effect

We report studies of magnetic field effect (MFE) in polymer light-emitting electrochemical cells (PLEC) using the "super-yellow" poly-(phenylene vynilene) (SY-PPV) polymer in vertical and planar device configurations. The purpose is to discern the existing MFE mechanisms in organic light emitting diodes (OLEDs) where the current and electroluminescence are strongly modulated by a small applied magnetic field. In particular, we investigate the mutual relationship between magneto-conductance (MC) and magneto-electroluminescence (MEL) by studying the role of polaron density dissociated from polaron pairs (PP) on these magnetic responses. In general, the dissociated polaron density is determined by the PP dissociation rate and the PP density. For the planar PLEC, which possesses a small dissociation rate, we observe small and negative MC at all applied voltages regardless of the emission intensity, while MEL becomes positive when electroluminescence quantum efficiency increases. The MC has a much narrower width than the MEL, indicating that the MC and MEL do not share a common origin. However, MC reverses and has the same width as MEL when the device is exposed to a threshold laser power. For the vertical PLEC, characterized by a large dissociation rate, MC and MEL are positive and have the same width. We discuss the results using the existing MFE mechanism in OLEDs. We show that the PP model can explain the positive MEL and MC, while the negative MC can be explained by the bipolaron model. Finally, we present a possibility to complete an all-organic PLEC magnetic sensor by using an inkjet printer.

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Evidence for the crucial role of nuclear spins for the magnetic field effect in polarization echoes in glasses

physica status solidi (c) ◽

10.1002/pssc.200405380 ◽

2004 ◽

Vol 1 (11) ◽

pp. 2875-2878 ◽

Cited By ~ 2

Author(s):

M. Brandt ◽

P. Nagel ◽

A. Fleischmann ◽

C. Enss ◽

S. Hunklinger

Keyword(s):

Magnetic Field ◽

Crucial Role ◽

Field Effect ◽

Magnetic Field Effect ◽

Nuclear Spins ◽

The Magnetic Field

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Role of viscosity in the magnetic field effect on pyrene–DMA exciplex emission at different permittivities

Chemical Physics Letters ◽

10.1016/j.cplett.2014.01.003 ◽

2014 ◽

Vol 593 ◽

pp. 145-149 ◽

Cited By ~ 4

Author(s):

Amit Kumar Jana ◽

Partha Roy ◽

Deb Narayan Nath

Keyword(s):

Magnetic Field ◽

Field Effect ◽

Magnetic Field Effect ◽

Exciplex Emission ◽

The Magnetic Field

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The Model for Calculation the Hall Effect Parameter

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2004.9.2.15161 ◽

2004 ◽

Vol 9 (2) ◽

pp. 129-138

Author(s):

J. Kleiza ◽

V. Kleiza

Keyword(s):

Magnetic Field ◽

Field Effect ◽

Magnetic Field Effect ◽

Mapping Method ◽

Sample Thickness ◽

System Of Nonlinear Equations ◽

Specific Resistivity ◽

Conformal Mapping Method ◽

Effect Parameter ◽

The Magnetic Field

A method for calculating the values of specific resistivity ρ as well as the product µHB of the Hall mobility and magnetic induction on a conductive sample of an arbitrary geometric configuration with two arbitrary fitted current electrodes of nonzero length and has been proposed an grounded. During the experiment, under the constant value U of voltage and in the absence of the magnetic field effect (B = 0) on the sample, the current intensities I(0), IE(0) are measured as well as the mentioned parameters under the effect of magnetic fields B1, B2 (B1 ≠ B2), i.e.: IE(β(i)), I(β(i)), i = 1, 2. It has been proved that under the constant difference of potentials U and sample thickness d, the parameters I(0), IE(0) and IE(β(i)), I(β(i)), i = 1, 2 uniquely determines the values of the product µHB and specific resistivity ρ of the sample. Basing on the conformal mapping method and Hall’s tensor properties, a relation (a system of nonlinear equations) between the above mentioned quantities has been found.

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