Photoelectrochemical and Raman characterization of In₂O₃ mesoporous films sensitized by CdS nanoparticles

Abstract

SummaryThe method of successive ion layer adsorption and reaction was applied for the deposition of CdS nanoparticles onto a mesoporous In2O3 substrate. The filling of the nanopores in In2O3 films with CdS particles mainly occurs during the first 30 cycles of the SILAR deposition. The surface modification of In2O3 with CdS nanoparticles leads to the spectral sensitization of photoelectrochemical processes that manifests itself in a red shift of the long-wavelength edge in the photocurrent spectrum by 100–150 nm. Quantum-confinement effects lead to an increase of the bandgap from 2.49 to 2.68 eV when decreasing the number of SILAR cycles from 30 to 10. The spectral shift and the widening of the Raman line belonging to CdS evidences the lattice stress on the CdS/In2O3 interfaces and confirms the formation of a close contact between the nanoparticles.

Synthesis and In Vitro Photodynamic Activities of an Integrin‐Targeting cRGD‐Conjugated Zinc(II) Phthalocyanine

“…No other modifications of indium oxide were detected in X‐ray diffraction (XRD) measurements. Regarding the crystal quality, we like to note that the linewidth of the Raman peaks at room temperature of our films is smaller than in any spectrum in previous publications 2–9.…”

“…Besides low‐cost applications using amorphous material, crystalline In 2 O 3 exhibits high electron mobilities 1 suggesting its use in transparent logic elements. In recent years, a notable number of papers on cubic (bixbyite‐type) In 2 O 3 have been published 2–9 reporting on its Raman spectrum which demonstrates a growing interest in the characterization of this material by Raman spectro‐scopy. In all of these cases, the spectrum was excited with light in the visible spectral range, i.e.…”

Band-gap and sub-band-gap photoelectrochemical processes at nanocrystalline CdS grown on ZnO by successive ionic layer adsorption and reaction method

“…where d is the particle size, С is a constant independent of the quantum energy [36]. The C constant can be estimated using the reported in [37] transmission spectra of CdS/In 2 O 3 films (where CdS NPs were grown by SILAR) with a thickness of around 40 nm that is much smaller than both the thickness of the present ZnO/CdS films and the excitation wavelengths. Assuming C ≈ 2×10 7 m -1 eV 1/2 , d = 10 -8 m, and E g = 2.4 eV, a function η abs (h) can be plotted in the Tauc coordinates for different k values (Fig.…”

Study of mesoporous CdS-quantum-dot-sensitized TiO2 films by using X-ray photoelectron spectroscopy and AFM

“…To sensitize the photocatalyst TiO 2 with cadmium sulfide quantum dots (QDs-CdS) is a well-established concept that is of great relevance in different applications. The most popular of these applications are photosensitized solar cells with high quantum yields [ 1 – 4 ] and the photocatalytic degradation of pollutants [ 5 – 6 ]. CdS, currently used as an efficient visible-light sensitizer, is a semiconductor that possesses a small band gap (2.4 eV) and suitable potential energies.…”