Effective Passivation of Exfoliated Black Phosphorus Transistors against Ambient Degradation

Unencapsulated, exfoliated black phosphorus (BP) flakes are found to chemically degrade upon exposure to ambient conditions. Atomic force microscopy, electrostatic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy are employed to characterize the structure and chemistry of the degradation process, suggesting that O2 saturated H2O irreversibly reacts with BP to form oxidized phosphorus species. This interpretation is further supported by the observation that BP degradation occurs more rapidly on hydrophobic octadecyltrichlorosilane self-assembled monolayers and on H-Si(111) versus hydrophilic SiO2. For unencapsulated BP field-effect…

• UD
  U.S. Department of Defense
• WM
  W. M. Keck Foundation
• OO
  Office of Naval Research

  Award: N00014-14-1-0669
• DO
  Division of Materials Research

  Award: DMR-1121262