Enhancement in structural, morphological, and optical properties of copper oxide for optoelectronic device applications

Abstract

In this study, copper oxide (CuO) specimens were successfully prepared by the hydrothermal process at altered calcination temperatures; 350, 450, and 550°C. The synthesized samples were analyzed through X-ray powder diffraction (XRD), scanning electron microscope (SEM), Raman, Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy to analyze the impact of calcination temperature on the structural, morphological, vibration spectra, functional group, and optical properties of CuO for optoelectronic device applications. XRD confirms the pure single-phase monoclinic structure of synthesized samples with no impurity phases and has good crystallinity with the development in calcination temperature. The average crystalline size, lattice constant, and porosity were found in the range of 3.98–5.06 nm; a = 3.4357 Å, b = 3.9902 Å, c = 4.8977 Å – a = 3.0573 Å, b = 3.9573 Å, c = 4.6892 Å; and 3.37–1.03%, respectively. SEM exhibited a variation in morphology by increasing calcination temperature. Raman spectra revealed that the CuO sample calcinated at 550°C with a stone-like shape having a large grain size of 3.25 μm exhibited that Raman peak intensity and the multiphonon band became stronger and sharper and exhibited higher intensity compared to the samples calcinated at 350 and 450°C. FTIR spectra confirmed that these synthesized specimens exhibited the peaks associated with the typical stretching vibrations of the Cu–O bond between 400 and 500 cm−1 exhibiting the formation of CuO. The energy bandgap was slightly reduced from 1.61 to 1.43 eV with the increase in the calcination temperature. The optical studies revealed that the calcination temperature of 550°C improves the optical properties of CuO by tuning its optical bandgap. The modified structural, morphological, and optical characteristics of the prepared CuO samples make them an appropriate candidate for optoelectronic device applications.

A review article on recent trends in effect of Dielectric and a.c. conductivity in transition metal oxide based CuO composite

“…decrease in value of dielectric constant (Real part of dielectric permittivity (ε') below ~150 K temperature matching directly to reported dielectric behavior of perovskite (CCTO) and Li & Ti substitute NiO. The dielectric constant (Real part of dielectric permittivity (ε') show almost temperature independent response in higher frequency regime and regular decrement in lower frequency range[13].Khan et alreport structural and dielectric properties of CuO and Mn modified CuO (Cu 1-x Mn x O, x = 0.0, 0.01, 0.03, 0.05) nanomaterials synthesized using conventional solid state reaction method. For this, CuO & MnO 2 has been mixed in appropriate stoichiometric proportion and calcined at 600 °C for 4 hour and sintered at 800 °C for 8 hours.…”

Highly Sensitive Diethylamine Detection at Room Temperature Using g-C3N4 Nanosheets Decorated with CuO Hollow Polyhedral Structures

“…Moreover, the polyhedron morphology of CuO is distinguished by the presence of (111) lattice planes on its terminal surfaces . The ideal temperature range for annealing materials is critical to avoid grain coarsening or phase shifts, as higher temperatures increase crystallinity, reduce defects, larger grain size, and improve the XRD diffraction peaks of CuO material. , The intensity of diffraction peaks may increase with higher annealing temperatures, indicating that the size of CuO crystallites might enhance sintering and lead to a larger grain size. The optimal temperature for generating CuO-400 HPSs is also found.…”