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Efficient Field Emission from Vertically Aligned Cu 2 O 1‐ δ (111) Nanostructure Influenced by Oxygen Vacancy
Author(s) -
Nandy Suman,
Thapa Ranjit,
Kumar Mohit,
Som Tapobrata,
Bundaleski Nenad,
Teodoro Orlando M. N. D.,
Martins Rodrigo,
Fortunato Elvira
Publication year - 2015
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201402910
Subject(s) - materials science , work function , field electron emission , vacancy defect , x ray photoelectron spectroscopy , nanostructure , scanning tunneling microscope , oxygen , quantum tunnelling , analytical chemistry (journal) , nanotechnology , electron , condensed matter physics , crystallography , optoelectronics , nuclear magnetic resonance , chemistry , physics , organic chemistry , quantum mechanics , chromatography , layer (electronics)
In the architecture described, cuprous oxide (Cu 2 O) is tamed to be highly (111) plane oriented nanostructure through adjusting the deposition postulate by glancing angle deposition technique. In the controlled atmosphere oxygen vacancy is introduced into the Cu 2 O crystal subsequently fostering an impurity energy state ( E im ) close to the conduction band. Our model of Cu 2 O electronic structure using density functional theory suggests that oxygen vacancies enhance the electron donating ability because of unshared d ‐electrons of Cu atoms (nearest to the vacancy site), allowing to pin the work function energy level around 0.28 eV compared to the bulk. This result is also complemented by Kelvin probe force microscopy analysis and X‐ray photoelectron spectroscopy method. Oxygen vacancy in Cu 2 O (Cu 2 O 1‐ δ ) exhibits promising field emission properties with interesting field electron tunneling behavior at different applied fields. The films show very low turn‐on and threshold voltages of value 0.8 and 2.4 V μm −1 respectively which is influenced by the oxygen vacancy. Here, a correlation between the work function modulation due to the oxygen vacancy and enhancement of field emission of Cu 2 O 1– δ nanostructure is demonstrated. This work reveals a promising new vision for Cu 2 O as a low power field emitter device.