Role of ITO nanoparticles embedded into electrospun ITO nanofibers

Abstract

Both crystallization and molecular density are significant to achieve high electrical conductivity of transparent electrodes. Herein, we investigated the embedding effects of indium tin oxide (ITO) nanoparticles (NPs) into ITO nanofibers (NFs) synthesized by utilizing an electrospinning technique from ITO precursor solutions. We found that the ITO NPs might act as nucleation seeds that initiate crystallization of ITO, evidenced by flake-like morphologies which cannot be observed without ITO NPs. XRD measurements reveal that the ITO is crystalline with a higher degree and the size of ITO crystallites increases in the presence of ITO NPs embedded into NFs. Embedding ITO NPs leads to the formation of short fibers, but there is still large space between fibers as they are vertically stacked in the films, resulting in low electrical conductivity. Interestingly, a high ratio of ITO NPs enhances the electrical conductivity, as compared to a low ratio, which we attribute to the high fiber density on substrates due to the formation of shorter ITO NFs. Our results highlight that the ITO NPs influence not only the ITO crystallization but also the lengths of NFs. High electrical conductivity of NF films can be obtained by a high degree of crystallization and the optimum NF length that reduces spaces between NFs in the films.

Recent advances in nanofiber-based flexible transparent electrodes

“…Metal has a high density of free-electron and is a kind of material with high electrical conductivity, ductility and thermal conductivity, which plays an important role in the field of electronics [36,45]. Certain oxides of metals, such as ITO, WO 3 , Al 2 O 3 , NiO, etc, have been widely used in the field of FTEs as raw materials for film electrodes due to their electrical transmission, optical transparency and catalysis [111][112][113][114].…”

“…in the visible light range. Compared with ITO film electrodes, it has higher electrical conductivity, and the mesh structure between the fibers improves the light transmittance of the electrodes [111,116].…”

Fabrication of Plasmonic Indium Tin Oxide Nanoparticles by Means of a Gas Aggregation Cluster Source

“…Despite the many advantages of ITO NPs, there are still significant challenges regarding the integration of the currently available deposition methods with industrial manufacturing processes. For instance, the large-scale industrial production of optical coatings most often relies on vacuum-based deposition methods and is not compatible with the widely developed wet-chemistry approaches 6 , 8 , 13 , 14 , 18 , 19 , 21 for synthesizing ITO NPs. Moreover, to the best of our knowledge, there are no alternative vacuum-compatible deposition processes for ITO NPs 22 despite the wide use of physical vapor deposition (PVD) techniques for ITO films.…”