Single-layer MoS2 - 2D semiconductors beyond graphene
After quantum dots, nanotubes and nanowires, two-dimensional materials in the shape of sheets with atomic-scale thickness represent the newest addition to the diverse family of nanoscale materials . Single-layer molybdenum disulphide (MoS2), a direct-gap semiconductor is a typical example of new graphene-like materials that can be produced using the adhesive-tape based cleavage technique originally developed for graphene. The presence of a band gap in MoS2 allowed us to fabricate transistors that can be turned off and operate with negligible leakage currents [1]. Furthermore, our transistors can be used to build simple integrated circuits capable of performing logic operations and amplifying small signals [2] [3].
I will report here on high-performance 2D MoS2 transistors with increased currents and transconductance due to enhanced electrostatic control [4]. Our devices also show current saturation for the first time in a 2D semiconductor. Electrical breakdown measurements of our devices show that MoS2 can support very high current densities, exceeding the current carrying capacity of copper by a factor of fifty. We have also successfully integrated graphene with MoS2 into heterostructures to form flash memory cells [5]. Next, I will show optoelectronic devices based on MoS2 that have a responsivity surpassing that of similar graphene devices by six orders of magnitude [6]. Finally, I will present temperature-dependent electrical transport and mobility measurements that show clear mobility enhancement due to the suppression of the influence of charge impurities with the deposition of an HfO2 capping layer [7] and metal-insulator transition in monolayer MoS2.
References
[1] Q. H. Wang et al., Nature Nanotech. 2012, 7, 699.
[2] B. Radisavljevic et al., Nature Nanotech. 2011, 6, 147.
[3] B. Radisavljevic, M. B. Whitwick and A. Kis, ACS Nano, 2011, 5, 9934.
[4] B. Radisavljevic, M. B. Whitwick and A. Kis, Appl. Phys. Lett. 2012, 101, 043103.
[5] D. Lembke and A. Kis, ACS Nano 2012, 6, 10070.
[6] S. Bertolazzi, D. Krasnozhon and A. Kis, ACS Nano 2013, 7, 3246-3252.
[7] O. Lopez-Sanchez et al., Nature Nanotech. 2013, doi: 10.1038/nnano.2013.100.
[8] B. Radisavljevic and A. Kis, Nature Materials 2013, doi: 10.1038/NMAT3687.
I will report here on high-performance 2D MoS2 transistors with increased currents and transconductance due to enhanced electrostatic control [4]. Our devices also show current saturation for the first time in a 2D semiconductor. Electrical breakdown measurements of our devices show that MoS2 can support very high current densities, exceeding the current carrying capacity of copper by a factor of fifty. We have also successfully integrated graphene with MoS2 into heterostructures to form flash memory cells [5]. Next, I will show optoelectronic devices based on MoS2 that have a responsivity surpassing that of similar graphene devices by six orders of magnitude [6]. Finally, I will present temperature-dependent electrical transport and mobility measurements that show clear mobility enhancement due to the suppression of the influence of charge impurities with the deposition of an HfO2 capping layer [7] and metal-insulator transition in monolayer MoS2.
References
[1] Q. H. Wang et al., Nature Nanotech. 2012, 7, 699.
[2] B. Radisavljevic et al., Nature Nanotech. 2011, 6, 147.
[3] B. Radisavljevic, M. B. Whitwick and A. Kis, ACS Nano, 2011, 5, 9934.
[4] B. Radisavljevic, M. B. Whitwick and A. Kis, Appl. Phys. Lett. 2012, 101, 043103.
[5] D. Lembke and A. Kis, ACS Nano 2012, 6, 10070.
[6] S. Bertolazzi, D. Krasnozhon and A. Kis, ACS Nano 2013, 7, 3246-3252.
[7] O. Lopez-Sanchez et al., Nature Nanotech. 2013, doi: 10.1038/nnano.2013.100.
[8] B. Radisavljevic and A. Kis, Nature Materials 2013, doi: 10.1038/NMAT3687.
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- ICMP (Arnaud Magrez, Raphaël Butté and Woflgang Harbich)
Contact
- A. Magrez