Preparation of Monodispersed Nanoparticles of Transparent Conductive Oxides

Abstract

Generally, indium-tin-oxides (ITO) thin film is prepared by the sputtering process with ITO target, but only 20 % of ITO yielded from the target is deposited on the substrate. Namely, about 80 % ITO is exhausted by the deposition elsewhere far from the substrate. The recycling process of indium is limited so that ca. 20 % ITO of the starting material is lost without any recovery. Even if the recycling of ITO has been carried out in this process, we should prepare ITO target of 5 times more than apparent use of ITO on film. If we change it to printing process from the sputtering, the reduction in ITO use is expected as ca. 50 %, considering the increase in film thickness by printing. Our target technology also includes ITO nanoink for the project. As a result, monodispersed ITO nanoparticles (NPs) with a cubic shape were fabricated by using quaternary ammonium hydroxide-assisted metal hydroxide organogels. These NPs have perfect uniformity in size with beautiful shape, and perfect single crystalline structure including Sn. As we were attempted to make thin film with ITO nanoink, it was successfully fabricated below 200 nm in thickness and the resistivity was drastically decreased below 1.0 × 10-3 Ω cm after heat treatments. GZO nanoink as substitute of ITO has also been developed.

ITO@SiO2 and ITO@{M6Br12}@SiO2 (M = Nb, Ta) Nanocomposite Films for Ultraviolet-Near Infrared Shielding

“…S2 † ). 20 Nevertheless, in order to ensure the integration of only one or two ITO NPs per inverse micelle, the NPs had to be fully dispersed in the water phase, i.e. no aggregates of ITO NPs were allowed.…”

“…In this study, as previously reported, solvothermal and sol-gel methods were used to synthesize the ITO NPs. 20 The starting compounds Ta 6 Br 14 (H 2 O) 4 $3H 2 O (TBH) and K 4 Nb 6 Br 18 (KNB) were synthesized according to a procedure that was previously published. 30,31 The experimental conditions for the microemulsion process were adapted from our previous work.…”

“…17,18 Currently solution-based processes are highly desirable for reducing the cost of these materials and as a viable alternative to the sputtering process for the synthesis of ITO NPs and ITO nano inks. [19][20][21][22] In parallel, our group has recently proposed the use of transition metal nanoclusters as UV-NIR blocking building blocks. In this regard, they were successfully tested for the development of nanocomposite coatings by electrophoretic deposition (EPD).…”

Embedding of inkjet-printed Ag-grid/ITO hybrid transparent electrode into a plastic substrate for flexible electronic devices

“…The solution process based on printing technology offers an opportunity to reduce the fabrication costs from the following viewpoints: (1) efficient materials utilization due to direct deposition of the desired material at a location where it should be patterned and (2) low investment cost of the manufacturing equipment and easy scalability for large-area electronics since the printing technology does not require complicated and expensive vacuum-based equipment [11][12][13][14][15]. Despite these advantages of the solution process, it is reported by many research groups that the material performance of the solution-prepared ITO films needs to be further improved compared to the sputtered ITO films [16][17][18]. The sheet resistance of the solution-prepared ITO films is usually one-order higher than that of the sputtered films with a similar transparency.…”