Percolation-Based Metal−Insulator Transition in Black Phosphorus Field Effect Transistors
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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date
2023-03-15
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Mcode
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en
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8
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ACS Applied Materials and Interfaces, Volume 15, issue 10, pp. 13299-13306
Abstract
The existence of a novel phenomenon, such as the metal-insulator transition (MIT) in two-dimensional (2D) systems, affords emerging functional properties that provide new aspects for future electronics and optoelectronics. Here, we report the observation of the MIT in black phosphorus field effect transistors by tuning the carrier density (n) controlled by back-gate bias. We find that the conductivity follows an n dependence as σ(n) ∝ n α with α ∼ 1, which indicates the presence of screened Coulomb impurity scattering at high carrier densities in the temperature range of 10-300 K. As n decreases, the screened Coulomb impurity scattering breaks down, developing strong charge density inhomogeneity leading to a percolation-based transition at the critical carrier density (n C). At low carrier densities (n < n C), the system is in the insulating regime, which is expressed by Mott variable range hopping that demonstrates the role of disorder in the system. In addition, the extracted average values of critical exponent δ are ∼1.29 ± 0.01 and ∼1.14 ± 0.01 for devices A and B, respectively, consistent with the 2D percolation exponent of 4/ 3, confirming the 2D percolation-based MIT in BP devices. Our findings strongly suggest that the 2D MIT observed in BP is a classical percolation-based transition caused by charge inhomogeneity induced by screened Coulomb charge impurity scattering around a transition point controlled by n through back-gate bias.Description
Keywords
BLACK PHOSPHORUS, metal−insulatortransition, Mott VRH,, ensity inhomogeneity, 2D percolation
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Citation
Ali, N, Lee, M, Ali, F, Ngo, T D, Park, H, Shin, H & YOO, W J 2023, ' Percolation-Based Metal−Insulator Transition in Black Phosphorus Field Effect Transistors ', ACS Applied Materials and Interfaces, vol. 15, no. 10, pp. 13299-13306 . https://doi.org/10.1021/acsami.2c22046