Abstract:

Investigation on organic semiconductors (OS) has greatly been motivated by device applications such as light-emitting diodes (LED), field-effect transistors and solar cells. Recent years, organic spintronics including spin injection and transport, magnetic-field effects in these materials has become a new hot subject of research. Especially a strong magnetic-field effect (OMFE), i.e. a low magnetic field (in the scale of ) can substantially change the electroluminescence, photoluminescence, photocurrent, and electrical-injection current, is relatively easy to be obtained in an OS compared to its inorganic counterparts. The importance of OMFE is largely due to its fundamental science research and technology applications. From model and DFT simulation separately we study the charge-spin relationship of injected carriers. Some interesting phenomena are obtained. Then from phenomenological dynamics and quantum non-adiabatic calculation we study the OMFE. The theoretical calculations are well consistent to experimental data. It is found that both density and mobility response to the applied magnetic field may be responsible to the apparent organic magnetoresistance (OMAR). The internal effect of polaron and bipolaron carriers, strong electron-phonon interaction, and the hyperfine interaction of hydrogen nuclei on OMAR are discussed.
 
 
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