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The relation between the average diameter of CNTs on Ni–Cu @ a‐C:H catalyst with the optical absorption edge and the optical dispersion parameters
Author(s) -
GOUDARZI S.,
DALOUJI V.,
SOLAYMANI S.
Publication year - 2021
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/jmi.12970
Subject(s) - materials science , band gap , analytical chemistry (journal) , absorption edge , dispersion (optics) , absorption (acoustics) , absorption spectroscopy , oscillator strength , spectral line , thin film , nanotechnology , optics , chemistry , composite material , optoelectronics , physics , chromatography , astronomy
Summary In this study, the average diameter of the grown CNTs on Ni–Cu NPs @ a‐C:H substrates were increased by increasing of Cu content. The obtained results indicated that by increase of Cu content, all films exhibited high‐absorption spectra; therefore, we were facing an increase in the energy gap of films. The values of d T /d λ and d R /d λ measurements for grown CNTs with 75% Cu shown that maximum values of optical band gap correspond to with values of 2.48 eV and 2.90 eV, respectively. It can be seen that with increase of average diameter of the grown CNTs, the values of Urbach energy of films were increased. The RBS and EDAX measurements were confirmed presence of Ni and Cu atoms into films. The films deposited with 75% Cu were more smooth. Films deposited with 75% Cu have more disordered. Films deposited with 75% Cu atoms have maximum values of the oscillator strength f and the dispersion energy E d about of 0.108 eV 2 and 0.0543 eV, respectively.