基于二维黑磷的自旋阀器件的输运性质研究

发布时间：2018-12-06 21:25

【摘要】：近年来,二维范德华晶体材料,如石墨烯、过渡金属硫化物,由于具有优良的物理、化学和力学特性,引起广大科研工作者的广泛关注。黑磷作为一种新的二维半导体材料,具有厚度可调的带隙和高迁移率等优良特性,在纳米电子器件和光电子器件具有重要应用前景。与此同时,理论预测黑磷具有较长的自旋扩散长度,适合于发展自旋电子器件,而目前没有基于二维黑磷材料的自旋输运研究报道。本文利用机械剥离块材黑磷制备二维黑磷材料的方法,结合微纳米加工工艺制备黑磷纳米器件,并研究器件的场效应特性和自旋相关输运性质。(1)首先制备了二维纯黑磷和掺杂黑磷的场效应晶体管,分别测试了黑磷器件的基本电学性质。实验结果表明黑磷是p-型半导体特性,并具有高开关比和高迁移率,同时发现掺杂能够显著提高黑磷器件的稳定性,这为后续的自旋阀研究奠定了良好基础。(2)制备了基于二维黑磷垂直结构的自旋阀器件,研究了温度、电流等因素对其输运性质的影响。在室温下,黑磷自旋阀器件的磁电阻效应为0.23%,在4 K时磁电阻效应高达0.57%。研究发现黑磷在自旋阀器件中表现为金属特性。这些研究结果表明二维黑磷材料有可能适合于发展诸如磁性存储和磁逻辑器件的自旋电子器件。(3)制备了基于二维黑磷的面内结构自旋阀器件,在10 K观测了0.27%的磁电阻效应,但在室温下没有观测到明显的自旋相关输运,其主要原因可能与样品的铁磁性层与黑磷的界面质量较差有关。
[Abstract]:In recent years two-dimensional van der Waals crystal materials such as graphene and transition metal sulfides have attracted wide attention due to their excellent physical chemical and mechanical properties. As a new two-dimensional semiconductor material, black phosphorus has many excellent properties, such as tunable thickness band gap and high mobility. It has an important application prospect in nano-electronic devices and optoelectronic devices. At the same time, the theoretical prediction of black phosphorus has a long spin diffusion length, which is suitable for the development of spin electronic devices. However, there is no research report on spin transport based on two-dimensional black phosphorus material. In this paper, two dimensional black phosphorus materials were prepared by mechanical stripping of black phosphorus. The field effect characteristics and spin dependent transport properties of the devices are also studied. (1) the two dimensional pure black phosphorus and black phosphorus-doped field effect transistors are fabricated and the basic electrical properties of the black phosphorus devices are tested respectively. The experimental results show that black phosphorus is a p-type semiconductor with high switching ratio and high mobility. It is also found that doping can significantly improve the stability of black phosphorus devices. This lays a good foundation for the further study of spin valves. (2) the spin valve devices based on two-dimensional black phosphorus vertical structure are fabricated, and the effects of temperature, current and other factors on their transport properties are studied. At room temperature, the magnetoresistance effect of the black phosphorus spin valve is 0.23 and the magnetoresistive effect is as high as 0.57 at 4 K. It is found that black phosphorus exhibits metal characteristics in spin valve devices. These results indicate that two-dimensional black phosphorus materials may be suitable for the development of spin electronic devices such as magnetic storage and magnetic logic devices. (3) In-plane spin valve devices based on two-dimensional black phosphorus have been fabricated. The magnetoresistance effect of 0.27% was observed at 10 K, but no apparent spin correlation transport was observed at room temperature, which may be due to the poor interface quality between ferromagnetic layer and black phosphorus.
【学位授予单位】：山西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ126.31;TN386

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