Printing functional nanostructures: a novel route towards nanostructuring of organic electronic devices via soft embossing, inkjet printing and colloidal self assembly of semiconducting polymer nanospheres

Abstract

A new method for nanostructure formation from conjugated polymers is presented: an aqueous dispersion of semiconducting polymer nanospheres (SPNs) is deposited by inkjet printing onto a polymer surface patterned by soft embossing. By interaction between the spheres and the undulated surface a self assembly process is triggered, resulting in the formation of SPN nanostructures determined by the template. Both template layer and assembled SPNs can be incorporated into a device structure. We demonstrate a light emitting structure for use in polymer light emitting devices including analyses by atomic force microscopy and Kelvin probe force microscopy.

Fabrication of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet and Screen Printing for the Detection of Hydrogen Sulfide

“…Shepherd and G. sensors is desirable for a variety of environmental and health and safety applications. Inkjet printing has been utilized as a means to fabricate sensors and other functional devices in whole or in combination with other production methodologies [4]. To date, a wide variety of materials (polymers, inorganic polymers, etc.)…”

Organic semiconductors for device applications: current trends and future prospects

“…Besides auxiliary underlayers, a polymer matrix was also used as a binder to improve the film quality deposited from OS-NP solutions, as it assisted in reducing the electric field singularities around the NPs that might result in pinholes in electronic devices. PVA [634], hexadecyl-modified poly(ethylene oxide) [632], and PEDOT:PSS [635][636][637] polymer matrices were used, in this context, successfully. Although, in this way, the film quality is improved, the additives staying in the NP films are not at all good for the optical and optoelectronic properties of OS-NPs.…”

“…In this context, it is useful to recollect that when a drop of OS-NP solution is placed on the surface of a substrate, the OS-NPs form a coffee-stain-like structure after evaporation of the solvent as described above; therefore, simple inkjet printing of OS-NP solutions cannot provide good film morphology. To take care of this problem, an aqueous dispersion of OS-NPs is deposited by inkjet printing onto a polymer surface patterned by soft embossing [632], wherein, due to interaction between the OS-NPs and the undulated surface, self-assembly is triggered, resulting in the formation of OS-NP-based nanostructures determined by the embossed template. This method is very appropriate for incorporating the OS-NPs into a device structure.…”

Organic Semiconductor Nanoparticle Film: Preparation and Application

“…To avoid this drawback, an aqueous dispersion of semiconducting polymer nanospheres is deposited by inkjet printing onto a polymer surface patterned by soft embossing. 55 By interaction between the spheres and the undulated surface a self assembly process is triggered, resulting in the formation of OSN nanostructures determined by the template. As shown in Figure 8, after a droplet of the OSN solution was printed on the surface of the structured polymeric template layer, OSNs assemble in the grooves of the embossed surface.…”

“…This kind of binder for the nanoparticles can also assist in the reduction of electric field singularities around the particles that may result in regions of pinhole formation in electronic devices. Poly(vinyl alcohol), 57 hexadecyl-modified poly(ethylene oxide) (PEO), 55 and PEDOT:PSS 58  60 are polymer matrixes used for this purpose. These binders have virtually no effect on the color characteristics of the electroluminescence spectrum since PVA, PEO, and PEDOT:PSS have a negligible absorption in the luminance regime of OSNs.…”