Design and Fabrication of Photonic Structured Organic Solar Cells by Electrospraying

Abstract

Photonic architectures in optoelectronic devices are comprised of uniform periodic structural arrangement which aids in improved interaction with light. The processing of such photonic arrays generally involves several steps of fabrication. This work proposes single-step fabrication of an equal submicron size porous photonic structure array through electrospraying. This distinctive approach involves a continuous supply of material with simultaneous removal of solvent for fabricating large area samples, compared to other processing techniques. The process optimization is carried out to regulate the pore diameter and spacing. Morphological studies showed the continuity of porous arrays extending to large areas of the order of millimeters. Optical investigations demonstrated that this uniform periodic topography assisted in improved light scattering and a consequent enhancement of light absorption. Further, the incorporation of this array structure in the active layer of organic photovoltaic devices is evaluated through both experiments and modeling. Modeling and simulations suggest that the optimized range of 200–500 nm pore size aids in higher current density. Experiments reveal an improvement of 18% in the photocurrent density at short circuit in the periodic array architecture compared to the planar reference. Therefore, in this study, a facile single-step novel method of obtaining photonic array structures with improved device performances is demonstrated.

Electrospray: More than just an ionization source

“…Polymer particles can be employed in the deposition of thin films as ES represents a convenient method that minimizes polymer consumption and allows precise control over the location of the deposit [78,165]. A single synthetic polymer is usually used for the production of thin films, which are particularly useful in photovoltaics [166], polymer light-emitting diodes [167], or controllable wetting of surfaces [168]. Unlike the deposition of polymer particles, the production of thin films does not require the processed solution to completely dry within the ES plume.…”

Fabrication of Transparent Polymer Optical Device Combined with Selective Visible‐Light Transmission and Zero‐Birefringence

“…Photonic crystal devices defined as periodic nanostructures of dielectric materials with different refractive indices, [ 23,27 ] particularly 3D PC devices, [ 28 ] promising complete control over the photons emission and transmission in space due to the complete photonic bandgaps attributed to their periodic nanostructures. [ 11,20,29,30 ] Although most emergency applications take advantage of light reflection properties in fundamental sciences (Related to reflective coatings on lenses, [ 31,32 ] sensors, [ 33–35 ] color pigments in paints and inks, [ 36,37 ] energy management, [ 38–40 ] waveguides for directing the propagation of light along a specific path, [ 41,42 ] highly reflective mirrors in laser cavities, [ 43,44 ] and many other optical components), and here in order to obtain high transparency, we subtly control the optical bandgap beyond visible light by controlling the size of the PC nanospheres. As shown in Figure a, the optical properties of transparent optical devices can be described by Bragg's law, as shown in the following equations, [ 45,46 ] where d is the distance between two neighboring crystalline planes in the (111) direction for a face‐centered cubic (fcc) close‐packed structure, and its relation with the sphere diameter D is shown in Equation ().…”

Multituning of Structural Color by Protonation and Conjugate Bases

“…Owing to their unique properties, PhCs have been extensively investigated for a wide range of applications, including solar cells, − photocatalysts, − waveguides, − anticounterfeiting systems, − and chemical or biological sensors. − PhCs can be fabricated by a number of methods, among which the self-assembly of block copolymers (BCPs) is considered an effective fabrication method because of the advancement in micro-phase separation, ease of functionalization, and stability of the resulting morphologies. − The micro-phase separation of BCPs consisting of one or more hydrophilic and hydrophobic group into various morphologies, such as spheres, cylinders, bicontinuous gyroids, and lamellae, is based on two parameters: volume fraction degree of polymerization and Flory–Huggins parameter . Apart from these benefits, the applicability of BCPs can be extended by combining with functional materials that can change the periodic distance or refractive index. − …”