有机自旋器件磁性渗透层中双极化子对自旋极化输运的影响

Effect of bipolarons on spin polarized transport in magnetic permeated sublayer of organic spin device

根据实验发现的有机器件如Co/有机半导体/La0.7Sr0.3Mn O3中磁性原子渗透现象,利用自旋漂移-扩散方程,理论研究了磁性渗透层中极化子-双极化子的转化对自旋极化输运的影响.研究发现:磁性渗透层具有不同于纯净有机层的迁移率和自旋反转时间,都将影响极化子-双极化子的转化,进而影响自旋极化的输运;在磁性渗透层中极化子自旋反转时间的劈裂是引起自旋弛豫的主要因素,而极化子和双极化子之间的转化是重要因素.

According to the permeation phenomenon of magnetic atoms in organic device, such as Co/organic semiconductor （OSC）/Lao.TSr0.aMnO3, the evolution of spin polarons and spinless bipolarons are calculated with the drift-diffusion equations to investigate the effect of polaron-bipolaron interaction on spin polarized transport in a magnetic permeated sublayer （MPS）. It is found that the MPS has different spin-flip time and mobility from those in pure organic semi- conductor. The splitting of spin-flip time will be adjusted by the effect of the magnetization of the impurity atoms. Mobilities of spin carriers in the MPS will be reduced due to the scattering of the Co atoms. Both the spin-flip time and the mobility will affect the polaron-bipolaron interaction and further influence the spin polarized transport. It is found that the splitting of spin-flip time is the main factor responsible for the spin relaxation, while the polaron-bipolaron interaction is the secondary factor.