Indium tin oxide
Thin films of ITO are also used in organic light-emitting diodes, solar cells, antistatic coatings and EMI shieldings.
The F-22 Raptor's canopy has an ITO coating that reflects radar waves, enhancing its stealth capabilities and giving it a distinctive gold tint.
[11] An improved method that embeds Ag nanoparticles (AgNPs) instead of homogeneously to create a hybrid ITO has proven to be effective in compensating for the decrease in transparency.
[citation needed] Because of the cost and energy of physical vapor deposition, with the required vacuum processing, alternative methods of preparing ITO are being investigated.
Benzyl phthalate plasticizer and polyvinyl butyral binder have been shown to be helpful in preparing nanoparticle slurries.
[17] There has been numerical modeling of plasmonic metallic nanostructures have shown great potential as a method of light management in thin-film nanodisc-patterned hydrogenated amorphous silicon (a-Si:H) solar photovoltaic (PV) cells.
Unfortunately, most work on TCOs is on relatively thick layers and the few reported cases of thin TCO showed a marked decrease in conductivity.
AZO is a common choice of transparent conducting oxide (TCO) because of its lower cost and relatively good optical transmission performance in the solar spectrum.
ITO is not affected by moisture, and is stable as part of copper indium gallium selenide solar cell for 25–30 years on a rooftop.
By stacking several cells with different sized rods, a broad range of wavelengths across the solar spectrum can be collected and converted to energy.
Moreover, the nanoscale volume of the rods leads to a significant reduction in the amount of semiconductor material needed compared to a conventional cell.
[22][23] Recent studies demonstrated that nanostructured ITO can behave as a miniaturized photocapacitor, combining in a unique material the absorption and storage of light energy.
Studies with animals indicate that indium tin oxide is toxic when ingested, along with negative effects on the kidney, lung, and heart.
[27] Silver nanoparticles existed in improved ITOs have been found in vitro to penetrate through both intact and breached skin into the epidermal layer.
Un-sintered ITOs are suspected of induce T-cell-mediated sensitization: on an intradermal exposure study, a concentration of 5% uITO resulted in lymphocyte proliferation in mice including the number increase of cells through a 10-day period.
Unlike uITO, they can also bring endotoxin to workers handling the wet process if in contact with endotoxin-containing liquids.
This can be attributed to the fact that sITOs have larger diameter and smaller surface area, and that this change after the sintering process can cause cytotoxicity.
[42] Several transition metal dopants in indium oxide, particularly molybdenum, give much higher electron mobility and conductivity than obtained with tin.
Other inorganic alternatives include aluminum, gallium or indium-doped zinc oxide (AZO, GZO or IZO).
[44][45] As another carbon-based alternative, films of graphene are flexible and have been shown to allow 90% transparency with a lower electrical resistance than standard ITO.
In order to reduce indium content, decrease processing difficulty, and improve electrical homogeneity, amorphous transparent conducting oxides have been developed.
One such material, amorphous indium-zinc-oxide maintains short-range order even though crystallization is disrupted by the difference in the ratio of oxygen to metal atoms between In2O3 and ZnO.
