In Situ Cleaning and Fluorination of Black Phosphorus for Enhanced Performance of Transistors with High Stability
- 19 August 2020
- journal article
- research article
- Published by American Chemical Society (ACS) in ACS Applied Materials & Interfaces
- Vol. 12 (33), 37375-37383
- https://doi.org/10.1021/acsami.0c11129
Abstract
Most two-dimensional (2D) semiconductors suffer from intrinsic instability under ambient conditions, especially 2D black phosphorus (BP). Although much effort has been made to study the passivation of 2D materials against corrosion by oxygen and water molecules, facile and effective passivation with long-term stability is still challenging; in particular, selective passivation, which is critical for integration into nanoelectronics, is still lacking. Here, we develop a novel passivation route for BP using a fluorinated self-assembled thin film of PFSA (perfluorosulfonic acid, PFSA), where the surface modifier with high hydrophobicity on BP presents extremely stable characteristics over five months under ambient conditions. Moreover, we report for the first time in situ cleaning and selective fluorination of only BP flakes on a SiO2 /Si substrate by a spin-coating process followed by ultrasonication, which was attributed to the formation of P-F covalent bonds on the BP surface. Selectively fluorinated BP shows not only enhanced stability in air but also electrical properties of the BP field-effect transistor (FET), with the on-current of the BP FET increasing and presenting enhanced carrier mobility (125 cm(2) V-1 s(-1)) and on/off ratio (10(4)). This significant finding sheds light on fabricating vertical 2D heterostructures to realize high performance and reliability with versatile 2D materials. This work demonstrates an emerging passivation approach for long-term stability together with superior electrical properties, which paves the way for integrating 2D semiconductors into critical channel materials in FETs that are favorable for next-generation digital logic circuits.Keywords
Funding Information
- Ministry of Science and Technology (105-2221-E-008-085-MY3, 109-2628-E-008-002-MY3)
This publication has 72 references indexed in Scilit:
- Environmental instability of few-layer black phosphorus2D Materials, 2015
- Effective Passivation of Exfoliated Black Phosphorus Transistors against Ambient DegradationNano Letters, 2014
- Device Perspective for Black Phosphorus Field-Effect Transistors: Contact Resistance, Ambipolar Behavior, and ScalingACS Nano, 2014
- Impact of Substrate and Processing on Confinement of Nafion Thin FilmsAdvanced Functional Materials, 2014
- Black phosphorus field-effect transistorsNature Nanotechnology, 2014
- Molecular origins of fluorocarbon hydrophobicityProceedings of the National Academy of Sciences, 2010
- Analysis by using X-ray photoelectron spectroscopy for polymethyl methacrylate and polytetrafluoroethylene etched by KrF excimer laserApplied Surface Science, 2006
- Analysis of Poly(tetrafluoroethylene) (PTFE) by XPSSurface Science Spectra, 1996
- The influence of preadsorbed K on the adsorption of PF3 on Ru(0001) studied by soft x-ray photoelectron spectroscopyThe Journal of Chemical Physics, 1994
- Raman and infrared reflection spectroscopy in black phosphorusSolid State Communications, 1985