Nano Cuprous Oxides Film Prepared by Magnetron Sputtering

Abstract

Cuprous oxide (Cu2O) is a direct-gap semiconductor with band-gap energy of 2.0 eV and has been extensively investigated as a candidate for a photovoltaic material. However, practical applications have not been achieved to date due to the difficulty in controlling its physical properties. We have investigated the controllability of the formation of pure Cu2O thin films deposited by the reactive DC sputtering method and analysis by XPS and Raman spectrometer to identify the Cu+1 in the cuprous oxide. The formation of pure Cu2O films is not only dependent on the substrate temperature but also strongly effected by the oxygen and argon flow rate ratio. When the substrate temperature was kept constant at 100°C and varied the oxygen and argon flow rate ratio from 3ml/min to 10ml/min, it is found a mixture of Cu2O and CuO phases is formed. At the flow rate of oxygen to 5ml/min, the pure and single phase of Cu2O is formed. Further increasing the oxygen flow rate, the phase is changed to be the CuO phase. The crystallity is improved as increasing the substrate temperature. The electrical resistivity of Cu2O obtained in this study is about 316 ohm-cm at 100°C substrate temperature and 2.66Pa condition. The dependence of cupper oxides resistivity is not only on the substrate temperature and reactive gases but also on the sputter pressure. Because the characteristic resistivity values change with sputter pressure variation due to different phase compositions forming in the films. The lowest resistivity of Cu2O film is obtained when the Cu2O single phase exists in the films.

Epitaxial growth and microstructure of Cu2O nanoparticle/thin films on SrTiO3(100)

“…Since the XRD data clearly show (figure 1) that the film consists of Cu 1+ we believe the sputtered surface mostly consists of Cu 1+ rather than Cu 0 . Moreover, in both the as-deposited and sputtered sample A, the main peaks of 2p 1/2 are located at a binding energy of 953.4 and 951.6 eV, respectively, consistent with the result reported in the literature [26]. The satellite feature observed in the as-deposited sample is a characteristic of materials such as copper dihalides, metallic nickel or CuO having a d 9 configuration in the ground state [12,25,27].…”

Nanostructured copper oxides as ethanol vapour sensors

“…5b). These results are in good agreement with a previous report by Lu et al and Ghijsen et al [12,41]. These energies further clarify the presence of the CuO and Cu 2 O phases in films obtained at 200 and 250 W, respectively.…”

“…6b. Four distinct peaks located at 113, 147, 215 and 631 cm −1 are observed and ascribed to Cu 2 O [12,44,45]. Thus, in terms of sample identification, the results of Raman spectroscopy are in agreement with those obtained from XRD and XPS.…”

“…In the family of metal oxide semiconductors, copper oxides (Cu x O -cuprous oxide (Cu 2 O) and cupric oxide (CuO)) are amongst the most promising materials for gas sensing due to their high absorption coefficients, favourable electronic structures and earth-abundance [11,12]. Copper oxides are intrinsic p-type semiconductors with relatively narrow energy band gaps of ∼1.2 eV (CuO) and ∼2.1 eV (Cu 2 O) that exhibit a variety of interesting properties, which can be fully exploited in gas and vapour sensors, including ethanol vapour.…”

Enhancing the current density of electrodeposited ZnO–Cu2O solar cells by engineering their heterointerfaces

“…7,12,13,15 ZnO and Cu 2 O can be prepared using different methods such as thermal oxidation, 16 electrodeposition, 4,15,[17][18][19] anodic oxidation, 20 pulsed laser deposition, 21 spraying, 22 thermal evaporation, 23,24 nanoparticle inks, 25 dc reactive magnetron sputtering 26 and rf reactive magnetron sputtering deposition. [27][28][29] Among the aforementioned methods, electrodeposition has several advantages such as low fabrication costs, facile control over film thickness, morphology and doping concentration, low temperature and low ambient pressure processing. 4,30 In addition, postannealing processes can be avoided as the deposited films are highly crystalline.…”