Field-effect transistors built from all two-dimensional material components.
We demonstrate field-effect transistors using heterogeneously stacked two-dimensional materials for all of the components, including the semiconductor, insulator, and metal layers. Specifically, MoS2 is used as the active channel material, hexagonal-BN as the top-gate dielectric, and graphene as the source/drain and the top-gate contacts. This transistor exhibits n-type behavior with an ON/OFF current ratio of >10(6), and an electron mobility of ∼33 cm(2)/V·s. Uniquely, the mobility does not degrade at high gate voltages, presenting an important advantage over conventional Si transistors where enhanced surface roughness scattering severely reduces carrier mobilities at high gate-fields. A WSe2-MoS2 diode with graphene contacts is also demonstrated. The diode exhibits excellent rectification behavior and a low reverse bias current, suggesting high quality interfaces between the stacked layers. In this work, all interfaces are based on van der Waals bonding, presenting a unique device architecture where crystalline, layered materials with atomically uniform thicknesses are stacked on demand, without the lattice parameter constraints. The results demonstrate the promise of using an all-layered material system for future electronic applications.
Electrical Engineering and Computer Sciences, University of California , Berkeley, California 94720, United States.
Tania
T
Roy
Mahmut
M
Tosun
Jeong Seuk
JS
Kang
Angada B
AB
Sachid
Sujay B
SB
Desai
Mark
M
Hettick
Chenming C
CC
Hu
Ali
A
Javey