Admittance spectroscopy study of polymer diodes in small magnetic fields

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Publication Type journal article
School or College College of Science
Department Physics
Creator Rogachev, Andrey
Other Author Djidjou, Thaddee K.; Basel, Tek
Title Admittance spectroscopy study of polymer diodes in small magnetic fields
Date 2012-01-01
Description We performed a systematic study of bipolar and unipolar organic diodes based on the p-conjugated polymer, 2-methoxy-5-(20-ethylhexyloxy) (MEH-PPV), using electronic and magneto-transport measurements with magnetic field in the range 0-180mT and admittance spectroscopy in the frequency range 1 Hz<f<10MHz. The admittance spectra of bipolar devices reveal two relaxation processes with distinct time scales that are influenced by the magnetic field. The slower process, which dominates the device capacitance at f<10 Hz, is attributed to the trap-assisted monomolecular recombination. The faster process is attributed to the electron-hole bimolecular recombination kinetics. We found that the time scale of this process, s2, decreases exponentially with the bias voltage. Application of magnetic field, B¼30mT decreases s2 by ~30%. We also found that the magneto-conductance, DGðx; BÞ=Gðx; 0Þ, has a characteristic cutoff frequency that shifts to higher frequencies with increasing bias voltage. In particular, the magnetoconductance at 10MHz in a bipolar device was measured to be 4.5% at B¼30mT. For bipolar devices we found that the frequency-dependent response of the device admittance to the small magnetic field is identical to the response of the admittance to a small increase in the bias voltage in zero magnetic field. We also found that the admittance of unipolar diodes does not depend on magnetic field.
Type Text
Publisher American Institute of Physics (AIP)
Volume 112
Issue 2
First Page 204511-1
Last Page 204511-9
Dissertation Institution University of Utah
Language eng
Bibliographic Citation Djidjou, T. K., Basel, T., & Rogachev, A. (2012). Admittance spectroscopy study of polymer diodes in small magnetic fields. Journal of Applied Physics, 112(2), 204511-1-204511-9.
Rights Management (c)American Institute of Physics. The following article appeared in Djidjou, T. K., Basel, T., & Rogachev, A. (2012). Admittance spectroscopy study of polymer diodes in small magnetic fields. Journal of Applied Physics, 112(2), 204511-1-204511-9. 2010 and may be found at http://dx.doi.org/10.1063/1.4737773.
Format Medium application/pdf
Format Extent 658,159 bytes
Identifier uspace,17907
ARK ark:/87278/s6z32hdk
Setname ir_uspace
Date Created 2012-10-09
Date Modified 2021-05-06
ID 708167
Reference URL https://collections.lib.utah.edu/ark:/87278/s6z32hdk
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