Effect of annealing on the properties of nanostructured CuO thin films for enhanced ethanol sensitivity

Assessment of CuO thin films for its suitablity as window absorbing layer in solar cell fabrications

“…Nair et al [22] could only achieve a deposition of Cu phase along with a minority Cu 2 O phase at room temperature by the chemical deposition technique. However in the present study, spray pyrolysis technique with specially designed spray nozzle and the optimized deposition parameters yielded only the single phase tenorite CuO phase with monoclinic structure at the lowest deposition temperature of 350 C. Obtained observations are reliable with the results reported by Gopalakrishna et al [27], Morales et al [24], Senthil Kumar et al [25] and Cho et al [26] for CuO films prepared by spray pyrolysis technique. In both the films, ð111Þ is the predominant crystallographic plane indicating a perpendicular alignment of the c-axis of the grains [23].…”

“…to the ð111Þ and (111) diffraction planes with interplanar distances 2.528 Å and 2.324 Å, respectively. As the concentration was increased to 0.2 M, the intensity of the prominent peaks also increased which is consistent with the results reported by Gopalakrishna et al [27]. Obtained values are in good agreement with standard data of CuO phase (JCPDS Card No.…”

Nanostructured copper and copper oxide thin films fabricated by hydrothermal treatment of copper hydroxide nitrate

“…It is due to the fact that various fields of new technologies from electronic devices to surface catalysts, self-cleaning, solar and fuel cells and even biology and environment phenomena depended on thin films [1][2][3][4][5][6][7]. To this end, a variety of organic and inorganic materials such as polymers, pure and doped metal oxides/hydroxides and carbon materials have been successfully coated onto different substrates for specific purposes.…”

Spray Deposited Nanostructured CuO Thin Films: Influence of Substrate Temperature and Annealing Process

“…The variation of the mobility is quite similar to the mean crystallite size trend which we believe shows the close correlation between crystallinity and mobility in the resulting films. This tendency in mobility might be attributed to the reduction in barrier height at the grain boundaries by virtue of a larger crystallite size at lower substrate temperatures 19,21 . It is well known that the p-type conductivity in CuO thin films are the direct result of Cu vacancies in lattice structure which leads to the formation of holes in valence bond 22 .…”

“…Both the mobility and carrier concentration in the annealed film meet a considerable raise in comparison with the as-deposited one, leading to a distinctive conductivity 23,24 . On the one hand, as a result of the annealing process, not only does the crystallite size increase, but the surface morphology also changes, which seems to be in favor of a better mobility 21 . However, it causes a better oxidation and therefore, a higher concentration of oxygen in nonstoichiometric CuO which increases the hole-carrier concentration in the annealed film 2 .…”