Laser treatment of ITO thin films with Carbon Nanotubes for Liquid Crystal Devices

In this paper, the influence of laser ablation on the refractive properties of indium tin oxides (ITO) thin films with deposited single-wall Carbon Nanotubes (CNTs) was considered. Sputtering of CNTs was preliminary based on the laser-oriented method with application of the external electric field. The laser ablation of ITO-CNTs coatings allows changing the electric, optical and mechanical properties dramatically. Moreover, this technical operation permit to switch the topology of the surface, thus it leads to the conversion of the refractive index. The possibility of index-matching due to the laser treatment contributes to the expansion of the technical capabilities of LC devices.

Near infrared photothermoelectric effect in transparent AZO/ITO/Ag/ITO thin films

A new concept of oxide-metal-oxide structures that combine photothermoelectric effect with high reflectance (~ 80%) at wavelengths in the infrared (> 1100 nm) and high transmittance in the visible range is reported here. This was observed in optimized ITO/Ag/ITO structure, 20 nm of Silver (Ag) and 40 nm of Indium Tin Oxide (ITO), deposited on Aluminum doped Zinc Oxide (AZO) thin film. These layers show high energy saving efficiency by keeping the temperature constant inside a glazed compartment under solar radiation, but additionally they also show a photothermoelectric effect. Under uniform heating of the sample a thermoelectric effect is observed (S = 40 mV/K), but when irradiated, a potential proportional to the intensity of the radiation is also observed. Therefore, in addition to thermal control in windows, these low emission coatings can be applied as transparent photothermoelectric devices.

Effect of Oxygen Flow Rate on Properties of Aluminum-Doped Indium-Saving Indium Tin Oxide (ITO) Thin Films Sputtered on Preheated Glass Substrates

Amorphous aluminum-doped indium tin oxide (ITO) thin films with a reduced indium oxide content of 50 mass% were manufactured by co-sputtering of ITO and Al2O3 targets in a mixed argon–oxygen atmosphere onto glass substrates preheated at 523 K. The oxygen gas flow rate and heat treatment temperature effects on the electrical, optical and structural properties of the films were studied. Thin films were characterized by means of a four-point probe, ultraviolet–visible-infrared (UV–Vis-IR) spectroscopy and X-ray diffraction. Transmittance of films and crystallization temperature increased as a result of doping of the ITO thin films by aluminum. The increase in oxygen flow rate led to an increase in transmittance and hindering of the crystallization of the aluminum-doped indium saving ITO thin films. It has been found that the film sputtered under optimal conditions showed a volume resistivity of 713 µΩcm, mobility of 30.8 cm2/V·s, carrier concentration of 2.9 × 1020 cm−3 and transmittance of over 90% in the visible range.

Enhancement of Electrical Properties of Sol–Gel Indium–Tin–Oxide Films by Microwave Irradiation and Plasma Treatment

We proposed the enhancement of the electrical properties of solution-processed indium–tin–oxide (ITO) thin films through microwave irradiation (MWI) and argon (Ar) gas plasma treatment. A cost- and time-effective heat treatment through MWI was applied as a post-deposition annealing (PDA) process to spin-coated ITO thin films. Subsequently, the sheet resistance of MWI ITO thin films was evaluated before and after plasma treatment. The change in the sheet resistance demonstrated that MWI PDA and Ar plasma treatment significantly improved the electrical properties of the ITO thin films. Furthermore, X-ray photoelectron spectroscopy and X-ray diffraction analyses showed that the electrical properties of the ITO thin films were enhanced by the increase in oxygen vacancies due to the ion bombardment effect of high-energy plasma ions during Ar plasma treatment. Changes in the band gap structure of the ITO thin film due to the ion bombardment effect were also analyzed. The combination of MWI PDA and Ar plasma treatment presents new possibilities for improving the high-conductivity sol–gel ITO electrode.

Near Infrared Photothermoelectric Effect in Transparent AZO/ITO/Ag/ITO Thin Films

A new concept of oxide-metal-oxide structures that combine photothermoelectric effect with high reflectance (~80%) at wavelengths in the infrared (> 1100 nm) and high transmittance in the visible range is reported here. This was observed in optimized ITO/Ag/ITO structure, 20 nm of Siver (Ag) and 40 nm of Indium Tin Oxide (ITO), deposited on Aluminum doped Zinc Oxide (AZO) thin film. These layers show high energy saving efficiency by keeping the temperature constant inside a glazed compartment under solar radiation, but additionally they also show a photothermoelectric effect. Under uniform heating of the sample a thermoelectric effect is observed (S = 40 μV/K), but when irradiated, a potential proportional to the intensity of the radiation is also observed. Therefore, in addition to thermal control in windows, these low emission coatings can be applied as transparent photothermoelectric devices.