title: Surface chemistry of black phosphorus under a controlled oxidative environment.
abstract: Black phosphorus (BP), the bulk counterpart of monolayer phosphorene, is a relatively stable phosphorus allotrope at room temperature. However, monolayer phosphorene and ultra-thin BP layers degrade in ambient atmosphere. In this paper, we report the investigation of BP oxidation and discuss the reaction mechanism based on the x-ray photoelectron spectroscopy (XPS) data. The kinetics of BP oxidation was examined under various well-controlled conditions, namely in 5% O2/Ar, 2.3% H2O/Ar, and 5% O2and 2.3% H2O/Ar. At room temperature, the BP surface is demonstrated not to be oxidized at a high oxidation rate in 5% O2/Ar nor in 2.3% H2O/Ar, according to XPS, with the thickness of the oxidized phosphorus layer <5 Å for 5 h. On the other hand, in the O2/H2O mixture, a 30 Å thickness oxide layer was detected already after 2 h of the treatment. This result points to a synergetic effect of water and oxygen in the BP oxidation. The oxidation effect was also studied in applications to the electrical measurements of BP field-effect transistors (FETs) with or without passivation. The electrical performance of BP FETs with atomic layer deposition (ALD) dielectric passivation or h-BN passivation formed in a glove-box environment are also presented.
authors.affiliation: School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China. Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA. School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Dmitry Y
authors.initials: DY
authors.lastname: Zemlyanov
authors.forename: Cory A
authors.initials: CA
authors.lastname: Milligan
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Du
authors.forename: Lingming
authors.initials: L
authors.lastname: Yang
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Wu
authors.forename: Peide D
authors.initials: PD
authors.lastname: Ye