Giant Carrier Mobility in Graphene with Enhanced Shubnikov–de Haas Quantum Oscillations: Implications for Low-Power-Consumption Device Applications

Graphene devices are susceptible to the surrounding environment. For example, the substrate in contact with graphene influences the device performance because the carriers are confined in two-dimensional (2D) atomic thickness. However, 2D van der Waals dielectric materials used as an interface modifier can provide a path to improve the device quality. In this paper, we report enhanced mobility of up to 540 000 cm2 V–1 s–1 in monolayer graphene sandwiched between two layers of a CrOCl insulator through a dielectric shielding effect. The Shubnikov–de Haas quantum oscillation is also observed with the amplitude linearly decreasing with increasing temperature, consistent with the standard Lifshitz–Kosevich theory. More strikingly, this oscillation persists to a temperature as high as 100 K because of this enhanced mobility. Our work paves a way to improve the mobility of graphene and realize the nontrivial quantum states at high temperatures for the exploration of low-power-consumption device applications in electronics.