肖特基势垒对铁磁/有机半导体结构自旋注入性质的影响

理论研究了铁磁/有机半导体肖特基接触时的电流自旋极化注入,并讨论了电流自旋极化率随界面处肖特基势垒高度、有机半导体层中特殊载流子及其迁移率、界面附近掺杂浓度的变化关系.通过计算发现,寻找在势垒区中载流子迁移率比较大的有机半导体材料对实现有效的自旋注入是必要的;同时还发现,由于铁磁/有机半导体接触而形成的肖特基势垒不利于自旋注入.因此要想实现有效的自旋注入,界面附近必须采用重掺杂来有效减少势垒区的宽度,且势垒的高度要限制在一定的范围内.

Effect of Schottky barrier on spin injection in ferromagnetic/organic semiconductor structure

Theoretically we have studied the current spin polarization in the structure of ferromagnetic/organic semiconductor under Schottky contact and discussed its variations with potential barrier height, the special carriers in organic semiconductor layer and the its mobilities, doping concentration near the interface. The calculations show that the high mobilities of the carriers in organic semiconductors are conducive to the spin injection. We also find that a significant depletion region at Schottky contact is highly undesirable for spin injection. For an efficient spin injection, the depletion region near the interface should be heavily doped and the effective barrier height should be restricted wichin certain range.