Optimisation of chemical solution deposition of indium tin oxide thin films

Abstract

An environmentally friendly aqueous sol-gel process has been optimised to deposit indium tin oxide (ITO) thin films, aiming to improve the film properties and reduce the deposition costs. It was demonstrated how parameters such as cation concentration and viscosity could be applied to modify the physical properties of the sol and thereby reduce the need for multiple coatings to yield films with sufficient conductivity. The conductivity of the thin films was enhanced by adjusting the heat treatment temperature and atmosphere. Both increasing the heat treatment temperature of the films from 530 to 800°C and annealing in reducing atmosphere significantly improved the electrical conductivity, and conductivities close to the state of the art sputtered ITO films were obtained. A pronounced decreased conductivity was observed after exposing the thin films to air and the thermal reduction and ageing of the film was studied by in situ conductivity measurements.

Modified Pechini Synthesis of Oxide Powders and Thin Films

“…After heat treatment at high temperatures and in reducing atmospheres, ITO thin films with excellent properties have been obtained. With a specific resistance down in the 10 -4 Ω·cm-range, the films prepared by the modified Pechini method are comparable to the best values from physical deposition techniques (Sunde et al 2014).…”

“…The microstructure of the resulting film is very dependent on the type of nucleation, being dependent on the pyrolysis temperature, heating rate and crystallization temperature (Schwartz et al 2004). The thickness of each deposited film can tailored from a few to a few hundred nanometers by varying the cation concentration and viscosity of the solution, or by changing the spinning or dipping speed (Bernardi et al 2002;Sunde et al 2014). The total thickness of the film can also be increased by repeating the deposition procedure.…”

“…For the deposition of ZnO thin films, He et al used a mixture of water and ethanol as solvent. In some cases it was shown that an additive, like PVA, was necessary in order to increase the viscosity of the solution and improve the wettability on the substrate (Kundu and Biswas 2008;Sunde et al 2014). The thickness of the films were tailored by the number of depositions, but also by varying the cation concentration and viscosity of the solution and by changing the spinning or dipping speed (Sunde et al 2014).…”

Marked Cofuel Tuning of Combustion Synthesis Pathways for Metal Oxide Semiconductor Films

“…To better understand the precursor thermolysis pathway and to quantify gaseous byproducts, TGA‐MS (mass spectrometry) analysis was performed on the dry CS IGZO, FACS 10 wt% VC/IGZO, 10 wt% Sor/IGZO, 10 wt% urea/IGZO, and 10 wt% Gly/IGZO precursors; results are shown in Figure h,i and Figure S4 in the Supporting Information. Unlike sol–gel precursors, which exhibit peaks from gaseous byproducts (e.g., NO, CO 2 ) at ≈400 °C, for all combustion precursors, a sharp increase in gaseous byproduct formation (H 2 O, NO, CO 2 ) is observed after 15–19 min (185–210 °C). After these times, for CS IGZO, the quantity of H 2 O (g) falls dramatically while other gases (NO and CO 2 ) continue to evolve until reaching 500 °C, indicating decomposition of the remaining organics.…”

Optical, Physical, Chemical and Electrical Properties of Nickel Oxide Sprayed Thin Films under Tin Doping Effects

“…Transparent conducting oxides (TCOs) such as zinc oxide [1], tin oxides [2] and indium oxide [3] have been attracted much attentions due to of their chemical and thermal stability.…”