A simple technology for CuO/TiO2 3D interface fabrication using nanocrystalline oxide powders

作者：Forcade Fresnel; Snyders Rony^*; Noirfalise Xavier; Gonzalez Bernardo; Laza Camila; Vigil Elena^*

来源：Semiconductor Science and Technology, 2017, 32(3): 035019.

DOI：10.1088/1361-6641/aa58d4

• CuO/TiO2
• nanocomposite
• interface
• CuO

A CuO/TiO2 interface with potential use for solar light conversion is studied. Thin films are synthesized using a mixture of commercially available nanocrystalline TiO2 and CuO powders. Samples with mass concentrations from 5 to 10% of CuO in TiO2 were prepared from a colloidal suspension using a 'doctor blade' technique. Heat treatment (500 degrees C, 1 h) was used to generate crystals necking and improve adhesion to substrates. X-ray diffraction analysis and scanning electron microscopy indicate that the CuO nanocrystals are smaller than those of TiO2. Since TiO2 does not absorb light in the spectral range where the CuO absorption edge is located, it was possible to obtain an effective CuO absorption coefficient spectra and then extract the bandgap energy. The results confirm the potential use of CuO as a TiO2 inorganic sensitizer for solar light. SEM images show a mesoporous structure for all samples that would facilitate penetration of a hole conductor and guarantee a large three-dimensional interface. Photocurrent direction with no bias confirms electron transfer from the CuO to the TiO2 when CuO/TiO2 films are used as photoelectrodes. Therefore, excited electrons in the CuO conduction band occupy levels with energy greater than the empty states in the TiO2 conduction band. Possible technological improvements to increase electron collection are discussed.

• 出版日期2017-3