The intrinsic acoustic-phonon-limited carrier mobility (μ) of Al2C monolayer sheet and nanoribbons are investigated using ab initio computation and deformation potential theory. It is found that the polarity of the room-temperature carrier mobility of the Al2C monolayer is direction-dependent, with μ of electron (e) and hole (h) being 2348 and 40.77 cm2/V/s, respectively, in the armchair direction and 59.95 (e) and 705.8 (h) in the zigzag direction. More interestingly, one-dimensional Al2C nanoribbons not only can retain the direction-dependent polarity but also may entail even higher mobility, in contrast to either the graphene nanoribbons which tend to exhibit lower μ compared to the two-dimensional graphene or the MoS2 nanoribbons which have reversed polarity compared to the MoS2 sheet. As an example, the Al-terminated zigzag nanoribbon with a width of 4.1 nm exhibits μ of 212.6 (e) and 2087 (h) cm2/V/s, while the C-terminated armchair nanoribbon with a width 2.6 nm exhibits μ of 1090 (e) and 673.9 (h) cm2/V/s; the C-terminated zigzag nanoribbon with a width 3.7 nm exhibits μ of 177.6 (e) and 1889 (h) cm2/V/s, and the Al-terminated armchair nanoribbon with a width 2.4 nm exhibits μ of 6695 (e) and 518.4 (h) cm2/V/s. The high carrier mobility, μ, coupled with polarity and direction dependence endows the Al2C sheet and nanoribbons with unique transport properties that can be exploited for special applications in nanoelectronics.
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry