Unraveling the temperature and voltage dependence of magnetic field effects in organic semiconductors

Abstract

Articles you may be interested inStudy of poly(3-hexylthiophene)/cross-linked poly (vinyl alcohol) In recent years, it was discovered that the current through an organic semiconductor, sandwiched between two non-magnetic electrodes, can be changed significantly by applying a small magnetic field. This surprisingly large magnetoresistance effect, often dubbed as organic magnetoresistance (OMAR), has puzzled the young field of organic spintronics during the last decade. Here, we present a detailed study on the voltage and temperature dependence of OMAR, aiming to unravel the lineshapes of the magnetic field effects and thereby gain a deeper fundamental understanding of the underlying microscopic mechanism. Using a full quantitative analysis of the lineshapes, we are able to extract all linewidth parameters and the voltage and temperature dependencies are explained with a recently proposed trion mechanism. Moreover, explicit microscopic simulations show a qualitative agreement to the experimental results. V C 2013 AIP Publishing LLC.

Magneto-Electroluminescence in ITO/MEH-PPV:PEO:LiCF3SO3/Al Polymer Light-Emitting Electrochemical Cells

“…Recently, spin-related physical phenomena in organic semiconductors have been widely studied. Magneto-electroluminescence (MEL)—that is, a change in the electroluminescence upon application of a magnetic field, has been observed in non-magnetic organic light emitting diodes (OLEDs), the MEL values and signs depend on the organic materials, applied voltage, and temperature [1,2,3,4,5]. With a decrease in temperature, the change of MEL shows divergence, e.g., it decreases for Alq 3 -based devices [6] and increases for MEH-PPV based OLEDs [7].…”

Trap-Filling Magnetoconductance as an Initialization and Readout Mechanism of Triplet Exciton Spins

“…There are many possible interactions that could change the device current in response to spin-dependent triplet–charge reactions. Are stable trions required in this mechanism, and do they exist in polycrystalline pentacene? While trion species are well-known in certain systems such as carbon nanotubes and semiconductor nanocrystals, it is unclear whether they exist as stable particles in most organic semiconductors. − …”