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Application of reflectance spectrophotometry to the study of copper (I) oxides (Cu 2 O and Cu 3 O 2 ) on metallic substrate
Author(s) -
Lefez B.,
Kartouni K.,
Lenglet M.,
Rönnow D.,
Ribbing C. G.
Publication year - 1994
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.740220196
Subject(s) - copper , photoluminescence , analytical chemistry (journal) , luminescence , stoichiometry , absorption (acoustics) , metal , diffuse reflectance infrared fourier transform , nucleation , band gap , substrate (aquarium) , spectroscopy , diffuse reflection , absorption spectroscopy , chemistry , materials science , transition metal , photocatalysis , catalysis , optics , metallurgy , oceanography , physics , chromatography , geology , biochemistry , optoelectronics , organic chemistry , quantum mechanics , composite material
The aim of this study is to characterize the compounds grown on copper during the oxidation at low temperature (T < 523 K) by optical methods: photoluminescence and UV‐Visible‐NIR diffuse reflectance spectroscopy. Two cuprous oxides Cu 2 O and Cu 3 O 2 have been studied. The absorption of Cu 2 O films in the range 450–630 nm is mainly due to non‐stoichiometry bands associated with copper and oxygen vacancies. Cu 3 O 2 is characterized by an optical band gap greater than that of Cu 2 O (respectively 2.25 and 1.95 eV) and by an intense luminescence emission at 760–780 nm. Cu 3 O 2 may be considered as a gross defect structure of Cu 2 O (a Cu 2 O= 0.427 nm, a Cu 3 O 2= 0.431 nm). The experimental approach of the oxidation mechanism reveals that at 423 K Cu 2 O is the primary product which later on is transformed into Cu 3 O 2 . Experimental and calculated optical absorption curves disclose the nucleation of CuO inside the cuprous oxides layer for oxidation in the range 473–523 K.