Probing the effects of thermal treatment on the electronic structure and mechanical properties of Ti-doped ITO thin films

Abstract

Titanium-doped indium tin oxide thin films were synthesized via a sol-gel spin coating process. Surface chemical bonding states and mechanical properties have been investigated as a function of titanium content (2 and 4 at%) and annealing temperature ranging from 400 to 600 °C with increments of 100 °C. Raman analysis was performed to study the phonon vibrations for the prepared samples and the results revealed the existence of ITO vibrational modes. The elemental compositions, bonding states and binding energies of the film materials were investigated using X-ray photoelectron spectroscopy (XPS) technique. The XPS results indicated that the ratio of the metallic elements (In, Sn, Ti) to the oxygen on the surface of the thin film coatings decreased due to the increase of the oxide layer on the surface of the thin films. Also, by increasing the annealing temperature up to 600 °C, the Ti 2p and Cl 2p signals were no longer detected for both 2 and 4 at% Ti contents, respectively, due to the thicker surface oxidation layer. Mechanical properties of the synthesized films were also evaluated using a nanoindentation process. Variations in the hardness (H) and the elastic modulus (E) were observed with different Ti at% and annealing temperatures. The hardness is within the range of 6.3–6.6 GPa and 6.7–6.8 GPa for 2 and 4 at% Ti content samples, respectively, while the elastic modulus is within the ranges of 137–143 and 139–143 GPa for 2 at% and 4 at% Ti contents samples, respectively. A combination of the highest H and E were achieved in the sample of 4% Ti content annealed at 600 °C. Furthermore, the H/E ratio ranges from 4.5 × 10−2 to 5.0 × 10−2 which reflects a reasonable level of wear resistance

Novel Approach for Fabricating Transparent and Conducting SWCNTs/ITO Thin Films for Optoelectronic Applications

“…The SWCNTs/ITO thin films in this study exhibited an increase in the wear resistance, which correlates to the increasing of H / E values, with increasing film thickness. The obtained H / E values, in the range of 8.7 × 10 –2 –9.3 × 10 –2 , indicate a higher level of wear resistance than that for pure ITO thin films . The mechanical properties of the SWCNTs/ITO thin films in this study are superior in comparison with our previously published results from Ti-doped ITO thin films; see Table .…”

“…The obtained H/E values, in the range of 8.7 × 10 −2 −9.3 × 10 −2 , indicate a higher level of wear resistance than that for pure ITO thin films. 79 The mechanical properties of the SWCNTs/ITO thin films in this study are superior in comparison with our previously published results from Ti-doped ITO thin films; see Table 4.…”

“…The obtained hardness and Young's modulus values for the samples in the present study are higher than those obtained from our previous study of Ti-doped ITO thin films. 79 The high values of hardness and Young's modulus of our SWCNTs/ITO thin films can be ascribed to uniformly incorporating SWCNTs in the ITO matrix. Winarto et al reported a similar effect from inclusion of CNTs in an alumina matrix.…”

Computational and performance studies of Ag2S–Bi2S3 quantum dot-sensitised solar cells

“…One of the reasons could be due to the unsuitable fabrication method for Bi 2 S 3 [16]. Aside from that, proper post heat treatment of the sample could help to improve the performance of the QDSSC [39]. Nevertheless, this work shows that the binary QD system has a better advantage in terms of chemical properties.…”

Electrical and optical enhancement of ITO/Mo bilayer thin films via laser annealing

“…For this purpose, many materials have been developed to improve the performance of optoelectronic devices. One of these materials is indium tin oxide (ITO), which combines high transparency with high conductivity [ 7 – 8 ]. However, a single layer of as-deposited ITO shows a high resistivity.…”