Limits...
Electrical spin injection and detection in molybdenum disulfide multilayer channel

View Article: PubMed Central - PubMed

ABSTRACT

Molybdenum disulfide has recently emerged as a promising two-dimensional semiconducting material for nano-electronic, opto-electronic and spintronic applications. However, the demonstration of an electron spin transport through a semiconducting MoS2 channel remains challenging. Here we show the evidence of the electrical spin injection and detection in the conduction band of a multilayer MoS2 semiconducting channel using a two-terminal spin-valve configuration geometry. A magnetoresistance around 1% has been observed through a 450 nm long, 6 monolayer thick MoS2 channel with a Co/MgO tunnelling spin injector and detector. It is found that keeping a good balance between the interface resistance and channel resistance is mandatory for the observation of the two-terminal magnetoresistance. Moreover, the electron spin-relaxation is found to be greatly suppressed in the multilayer MoS2 channel with an in-plane spin polarization. The long spin diffusion length (approximately ∼235 nm) could open a new avenue for spintronic applications using multilayer transition metal dichalcogenides.

No MeSH data available.


Multilayer MoS2-based lateral spin-valve device.(a) Optical image of the device with the multilayer MoS2 flake on 100 nm SiO2/Si(n++) substrate, the E1, E2, E3 and E4 indicate the four Au/Co/MgO electrodes. (b,c) AFM measurement (in tapping mode) focused on the MoS2 channel between E1 and E2 electrodes. The thickness of MoS2 is determined by the Gaussian distribution of pixel height in the square region in b. (d) Schematics of the lateral spin-valve device. The multilayer MoS2 serves as a spin transport channel, and two Au/Co/MgO electrodes are used to inject spin (Vds) and measure the current (Ids). A back-gate voltage (Vg) between the substrate and one top contact is used to modulate the carrier density in the MoS2 channel.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5385572&req=5

f1: Multilayer MoS2-based lateral spin-valve device.(a) Optical image of the device with the multilayer MoS2 flake on 100 nm SiO2/Si(n++) substrate, the E1, E2, E3 and E4 indicate the four Au/Co/MgO electrodes. (b,c) AFM measurement (in tapping mode) focused on the MoS2 channel between E1 and E2 electrodes. The thickness of MoS2 is determined by the Gaussian distribution of pixel height in the square region in b. (d) Schematics of the lateral spin-valve device. The multilayer MoS2 serves as a spin transport channel, and two Au/Co/MgO electrodes are used to inject spin (Vds) and measure the current (Ids). A back-gate voltage (Vg) between the substrate and one top contact is used to modulate the carrier density in the MoS2 channel.

Mentions: In our devices, MoS2 flakes were mechanically exfoliated onto a SiO2/Si (n++) substrate. Four FM contacts composed of MgO (2 nm)/Co (10 nm)/Au (10 nm) were deposited on one MoS2 flake (see details in Methods). The four electrodes have almost identical width around 300 nm with channel distances varying from 450 to 2,800 nm (Fig. 1a). The thickness of the flake is determined by atomic force microscopy characterization to be about 4.3 nm (Fig. 1b,c). Considering 0.72 nm for one ML MoS2 (ref. 27), the thickness of the flake corresponds to 6ML MoS2. Figure 1d shows schematics of the device. A drain-source bias (Vds) between two top contacts was applied to inject a current Ids. Meanwhile, a back-gate voltage (Vg) was applied between the substrate and one top contact to modulate the carrier density in the MoS2 channel.


Electrical spin injection and detection in molybdenum disulfide multilayer channel
Multilayer MoS2-based lateral spin-valve device.(a) Optical image of the device with the multilayer MoS2 flake on 100 nm SiO2/Si(n++) substrate, the E1, E2, E3 and E4 indicate the four Au/Co/MgO electrodes. (b,c) AFM measurement (in tapping mode) focused on the MoS2 channel between E1 and E2 electrodes. The thickness of MoS2 is determined by the Gaussian distribution of pixel height in the square region in b. (d) Schematics of the lateral spin-valve device. The multilayer MoS2 serves as a spin transport channel, and two Au/Co/MgO electrodes are used to inject spin (Vds) and measure the current (Ids). A back-gate voltage (Vg) between the substrate and one top contact is used to modulate the carrier density in the MoS2 channel.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5385572&req=5

f1: Multilayer MoS2-based lateral spin-valve device.(a) Optical image of the device with the multilayer MoS2 flake on 100 nm SiO2/Si(n++) substrate, the E1, E2, E3 and E4 indicate the four Au/Co/MgO electrodes. (b,c) AFM measurement (in tapping mode) focused on the MoS2 channel between E1 and E2 electrodes. The thickness of MoS2 is determined by the Gaussian distribution of pixel height in the square region in b. (d) Schematics of the lateral spin-valve device. The multilayer MoS2 serves as a spin transport channel, and two Au/Co/MgO electrodes are used to inject spin (Vds) and measure the current (Ids). A back-gate voltage (Vg) between the substrate and one top contact is used to modulate the carrier density in the MoS2 channel.
Mentions: In our devices, MoS2 flakes were mechanically exfoliated onto a SiO2/Si (n++) substrate. Four FM contacts composed of MgO (2 nm)/Co (10 nm)/Au (10 nm) were deposited on one MoS2 flake (see details in Methods). The four electrodes have almost identical width around 300 nm with channel distances varying from 450 to 2,800 nm (Fig. 1a). The thickness of the flake is determined by atomic force microscopy characterization to be about 4.3 nm (Fig. 1b,c). Considering 0.72 nm for one ML MoS2 (ref. 27), the thickness of the flake corresponds to 6ML MoS2. Figure 1d shows schematics of the device. A drain-source bias (Vds) between two top contacts was applied to inject a current Ids. Meanwhile, a back-gate voltage (Vg) was applied between the substrate and one top contact to modulate the carrier density in the MoS2 channel.

View Article: PubMed Central - PubMed

ABSTRACT

Molybdenum disulfide has recently emerged as a promising two-dimensional semiconducting material for nano-electronic, opto-electronic and spintronic applications. However, the demonstration of an electron spin transport through a semiconducting MoS2 channel remains challenging. Here we show the evidence of the electrical spin injection and detection in the conduction band of a multilayer MoS2 semiconducting channel using a two-terminal spin-valve configuration geometry. A magnetoresistance around 1% has been observed through a 450 nm long, 6 monolayer thick MoS2 channel with a Co/MgO tunnelling spin injector and detector. It is found that keeping a good balance between the interface resistance and channel resistance is mandatory for the observation of the two-terminal magnetoresistance. Moreover, the electron spin-relaxation is found to be greatly suppressed in the multilayer MoS2 channel with an in-plane spin polarization. The long spin diffusion length (approximately ∼235 nm) could open a new avenue for spintronic applications using multilayer transition metal dichalcogenides.

No MeSH data available.