Silicene field-effect transistors operating at room temperature

ROM 2015-11
Author: deji@ece.utexas.edu; alessandro.molle@mdm.imm.cnr.it
Publication: NATURE NANOTECHNOLOGY | VOL 10 | MARCH 2015
Instrument: VT SPM

Free-standing silicene, a silicon analogue of graphene, has a buckled honeycomb lattice1 and, because of its Dirac bandstructure2,3 combined with its sensitive surface, offers the potential for a widely tunable two-dimensional monolayer, where external fields and interface interactions can be exploited to influence fundamental properties such as bandgap4 and band character5 for future nanoelectronic devices6,7.

The quantum spin Hall effect3, chiral superconductivity8, giant magnetoresistance9 and various exotic field-dependent states7 have been predicted in monolayer silicene. Despite recent progress regarding the epitaxial synthesis of silicene8–10 and investigation of its electronic properties11,13–15, to date there has been no report of experimental silicene devices because of its air stability issue16. Here, we report a silicene field-effect transistor, corroborating theoretical expectations regarding its ambipolar Dirac charge transport17, with a measured roomtemperature mobility of ∼100 cm2 V–1 s–1 attributed to acoustic phonon-limited transport18 and grain boundary scattering.
These results are enabled by a growth–transfer–fabrication process that we have devised—silicene encapsulated delamination with native electrodes. This approach addresses a major challenge for material preservation of silicene during transfer and device fabrication and is applicable to other air-sensitive two-dimensional materials such as germanene2–4 and phosphorene19,20. Silicene’s allotropic affinity with bulk silicon and
its low-temperature synthesis compared with graphene or alternative two-dimensional semiconductors suggest a more direct integration with ubiquitous semiconductor technology.

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Authors: Li Tao1, Eugenio Cinquanta2, Daniele Chiappe2, Carlo Grazianetti2, Marco Fanciulli2, Madan Dubey3,Alessandro Molle2* and Deji Akinwande1*

1: Microelectronics Research Centre, The University of Texas at Austin, Texas 78758, USA.

2: Laboratorio MDM, IMM-CNR, via C. Olivetti 2, Agrate Brianza,
I-20864, Italy.

3: Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, Maryland 20723, USA.

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