Annealing effects on the properties of copper oxide thin films prepared by chemical deposition

Abstract

We have investigated the annealing effect on the structural, optical and electrical properties of copper oxide films prepared on glass substrates by chemical deposition. The films were annealed in air for different temperatures ranging from 200 to 350 • C. X-ray diffraction patterns showed that the films as-deposited and annealed at 200 and 250 • C are of cuprite structure with composition Cu 2 O. Annealing at 300 • C converts these films to CuO. This conversion is accompanied by a shift in the optical band gap from 2.20 eV to 1.35 eV. Also this conversion was obtained by the dc electrical conductivity and FTIR spectroscopy measurements.

Examination of interfacial charge transfer in photocatalysis using patterned CuO thin film deposited on TiO2

“…The formation of CuO has been confirmed also by the visible light absorption spectra (supplementary material S3): 15 the absorption starts around 900 nm, which agrees with the bandgap of bulk CuO of 1.3-1.4 eV. 16,17 Next, we investigated the photocatalytic reaction sites in the patterned CuO/TiO 2 films by the probe photo-reduction of silver ions (Ag + ) into metallic Ag particles. Patterned CuO/TiO 2 samples were immersed in 1.0 mM aqueous solution of silver nitrate (AgNO 3 ) and the CuO film was then irradiated with blue light emitting diode (LED) light for 1 h. The photodeposition of Ag particles on the CuO films with thicknesses of 100 nm ( Fig.…”

Oxidation mechanism of thin Cu films: A gateway towards the formation of single oxide phase

“…15 On the other hand, CuO appears in monoclinic structure (a = 0.4684 nm, b = 0.3423 nm, c = 0.5128 nm and β = 99.54 • ) with an indirect bandgap in the range of 1.21 -1.50 eV. 16 This material has potential use in the field of gas sensor applications, 17,18 along with magnetic storage media, 19 solar energy transformation, 20 varistors and catalysis as well. 21 Although, there are several reports on the exploitation of Cu 2 O as an active layer for solar cells, the conversion efficiencies of them are still much lower (∼2%) as compared to its theoretical value of around 20%.…”

Studies on chemical bath deposited CuO thin films for solar cells application

“…The hallmark of CBD is its simplicity, low cost, mild reaction conditions, reproducibility, excellent material utilization efficiency, good control over deposition process, and feasibility for large area deposition. To date, only a very few reports are available on the fabrication of CuO thin films by CBD method and the results are scattered and those reports hardly discuss the effect of solution pH, a key parameter in any chemically growth [14,15]. Hence, we have planned to carry out a systematic investigation of solution pH effect on CBD deposition and characterization of CuO thin films.…”