Morphology Tuning of ZnO/P3HT/P3HT-b-PEO Hybrid Films Deposited via Spray or Spin Coating

Abstract

Hybrid films of zinc oxide (ZnO) and poly(3-hexylthiophen-2,5-diyl) (P3HT) show promising characteristics for application in hybrid bulk-heterojunction solar cells (HBSCs). However, the incompatibility of ZnO and P3HT may lead to a reduced interface area, thus reducing the probability of exciton separation and consequently lowering solar cell efficiencies. Here, a diblock copolymer P3HT-bpoly(ethylene oxide) (PEO) is introduced to improve the interface between ZnO and P3HT. ZnO is synthesized via a block copolymer assisted sol−gel approach, and the used zinc precursor is directly incorporated into the PEO blocks. Thus, the possibility of aggregation is reduced for both the inorganic and the organic components, and a good intermixing is ascertained. Two deposition methods, namely, spray and spin coating, are compared with respect to the resulting film structure, which is investigated with scanning electron microscopy and time-of-flight grazing-incidence small-angle neutron scattering measurements. Both the surface and inner morphologies reveal that the spin coated samples possess smaller and less diverse domain sizes than the sprayed films. Due to the advantage of spray coating in large-scale production, the morphology of the sprayed samples is tailored more meticulously by changing the weight fraction of ZnO in the films. The sprayed hybrid films show smaller domains and less aggregation with decreasing the amount of ZnO. This reveals that both the deposition method and composition of the ZnO/P3HT/P3HT-b-PEO hybrid films play an important role for tailoring the film morphology and thus for improving the performance of HBSCs in future application.

Using Grazing-Incidence Small-Angle Neutron Scattering to Study the Orientation of Block Copolymer Morphologies in Thin Films

“…Neutrons are also uniquely sensitive to hydrogen and its isotope, deuterium. , With suitable instrumentation, GISANS has been increasingly used over the past three decades . Müler-Buschbaum pioneered the earliest studies on thin films by GISANS in an extensive series of studies on polymer thin films about surface roughness, interdiffusion of polymers, single-chain conformations, , dewetting of homopolymers and copolymers, − hydration of micelles, adhesive-adherent interfaces, and composite materials for photovoltaic, − magnetic, , and Li-ion battery applications. , Felcher and Adenwalla investigated Zeeman splitting when polarized neutrons impinged on a ferromagnetic surface at a grazing angle . GISANS has since been widely used to study micelles − and other nanomaterials near surfaces and interfaces .…”

Spin‐spray‐assisted layer‐by‐layer assembly of thick polymer films with self‐healing, UV‐protection, and anti‐fog properties

“…[17][18][19][20][21][22][23][24][25][26][27][28] The spray coating offers the advantages of easy up-scalability. 29 Combing the spin and spray method with a higher concentration of polyelectrolyte solutions is a feasible way to obtain homogeneous polymer films with tens of micrometers in thickness. Herein, a spin-spray-assisted (SSA-LbL) film assembly technique was developed to fabricate a thick polymer film with the merits of time and material-saving, compared with other LbL assembly methods.…”

“…The spin coating has been widely used to disperse the high viscosity materials on the planar substrate and create highly organized multilayers 17–28 . The spray coating offers the advantages of easy up‐scalability 29 . Combing the spin and spray method with a higher concentration of polyelectrolyte solutions is a feasible way to obtain homogeneous polymer films with tens of micrometers in thickness.…”

Experimental investigation on the influence of carbon-based nanoparticle coating on the heat transfer characteristics of the microprocessor

“…27 Spin-coated films have an increase in interface area and high heat transfer rate for heat removal process in large-scale fabrication. 24,28 The spin-coated graphene films exhibit highly ordered lamellar structure with high orientation of graphene which provides constant thermally conductive pathways. 29 From the previous literatures, it was found that various heat transfer techniques like TIM-based nanopaste materials and thin film coating techniques were used to analyze the performance of electronic components.…”