Electronic transport properties and magnetoresistance in the Fe3O4/SiO2/p-Si heterostructure with an in-plane current geometry.
Electronic transport properties and magnetoresistance in the Fe3O4/SiO2/p-Si heterostructure with an in-plane current geometry.
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DOI：
10.1039/c9cp00033j
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发表时间：
2019-04
期刊：
影响因子：
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通讯作者：
Xiang Liu;W. Mi
中科院分区：
文献类型：
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作者：
Xiang Liu;W. Mi
在传统的电子设备中，电子电荷被操纵以实现不同的功能。传统半导体中电子自旋的控制增加了自旋相关输运性质发生的可能性。在此，电子自旋注入到具有面内几何形状的Si晶片中是通过充当自旋注入器的Fe 3 O 4来实现的。在高温下，Fe 3 O 4的电阻率远小于p-Si晶片的电阻率。此外，在190 K以上，电流-电压（I-V）特性和磁阻（MR）的建议异质结构是由一个多晶Fe 3 O 4膜的本征性质为主，和面内电流在Fe 3 O 4层流动。由于Fe 3 O 4在低温下的电阻率增加，面内导电沟道逐渐从Fe 3 O 4切换到Si。Fe_3O_4的自旋注入在p-Si中形成了自旋极化的空间电荷区。由于电子在p-Si中的自旋相关输运，该异质结构在90 K下显示高达-76.1%的MR。随着温度的进一步降低，由于Fe 3 O 4/SiO2/p-Si界面处的能带弯曲，异质结构的I-V特性在80 K以下表现出负微分电阻。
In traditional electronic devices, the electronic charge is manipulated to realize different functions. The fascinating control of electronic spin in conventional semiconductors increases the probability of occurrence of spin-dependent transport properties. Herein, the injection of electronic spin into a Si wafer with in-plane geometry was achieved by Fe3O4, which acted as a spin injector. At high temperatures, the resistivity of Fe3O4 is far less than that of a p-Si wafer. Moreover, above 190 K, the current-voltage (I-V) characteristic and magnetoresistance (MR) of the proposed heterostructure are dominated by the intrinsic properties of a polycrystalline Fe3O4 film, and the in-plane current flows in the Fe3O4 layer. Due to the increased resistivity of Fe3O4 at low temperatures, the in-plane conductive channel gradually switches from Fe3O4 to Si. The spin injection from Fe3O4 results in a spin-polarized space charge region in p-Si. The heterostructure shows an MR of up to -76.1% at 90 K due to the spin-dependent transport of electrons in p-Si. With a further decrease in temperature, the I-V characteristic of the heterostructure shows negative differential resistance below 80 K due to band bending at the Fe3O4/SiO2/p-Si interface.