Electric Field-Induced Charge Carrier Density Driven Metal-to-Insulator Phase Transition in Few-Layered As-bP Field-effect Transistor*

Metal-to-insulator phase transitions (MIT) in 2D Systems is a controversial topic in condensed matter physics due to the fact that it challenges the prediction made by Abrahams et al., which states that two-dimensional disordered electronic systems must be insulating (Phys. Rev. Lett. 42, 673 (1979)). Recent studies^1,2 have indicated a possible MIT in few-layered transition metal dichalcogenide such as MoS₂, ReS₂ and CuIn₇Se₁₁³, but the mechanism leading to the MIT still remains enigmatic. We will present a possible MIT in few-layered As-doped black phosphorus from conductivity measurements in field effect transistors measured from 300 K to 2 K reveal an insulating-to-metallic-like phase transition when the carrier density is tuned via an applied gate voltage. The nature of the phase transition will be discussed with existing theoretical model. ¹Nat Commun. 2018; 9: 2052, ² Nano Lett. 2015, 15, 12, 8377, ³ACS Nano 2019, 13, 11, 13413