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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Oxygen impact on the electronic and vibrational properties of black phosphorus probed by synchrotron infrared nanospectroscopy

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Author(s):
Grasseschi, D. ; Bahamon, D. A. ; Maia, F. C. B. ; Castro Neto, A. H. ; Freitas, R. O. ; de Matos, C. J. S.
Total Authors: 6
Document type: Journal article
Source: 2D MATERIALS; v. 4, n. 3 SEP 2017.
Web of Science Citations: 9
Abstract

Black phosphorus (BP) is a layered crystalline structure presenting a thickness-tunable direct bandgap and a high charge carrier mobility, with, therefore, enormous interest to photonics, optoelectronics and electronics. However, BP's high susceptibility to oxidation when exposed to ambient conditions is a critical challenge for its implementation into functional systems. Here, we investigate the degradation of BP flakes exposed to various environmental conditions by synchrotron infrared nanospectroscopy (SINS). As a near-field based technique, SINS provides sub-diffractional mid-infrared images and spectra from nano-sized domains. Supported by density functional theory (DFT) calculations, our SINS spectra reveal the formation of nanoscale POx domains, with x between 0.5 and 1, and a 100 meV red shift in the bandgap of flakes exposed to air for a few minutes. On the other hand, exposure to air for 24 h led to the preferential formation of H3PO4, with complete removal of the electronic transitions from the mid-infrared spectral window, while a long (1 month) exposure to low O-2 levels mainly led to the formation of P4O8 and P4O9 species. The SINS analysis allows correlating the morphology of oxidized samples to the oxide type, thus, contributing to a comprehensive characterization of the BP degradation process. (AU)

FAPESP's process: 15/10405-3 - Synthesis, characterization, functionalization and ordering of metallic nanostructures
Grantee:Daniel Grasseschi
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 15/11779-4 - Plasmonic and nonlinear effects in graphene coupled to optical waveguides
Grantee:Christiano José Santiago de Matos
Support type: Research Projects - Thematic Grants
FAPESP's process: 12/50259-8 - Graphene: photonics and opto-electronics: UPM-NUS collaboration
Grantee:Antonio Helio de Castro Neto
Support type: Research Projects - SPEC Program