Morphology of a Ternary Blend Solar Cell Based on Small Molecule:Conjugated Polymer:Fullerene Fabricated by Blade Coating

Abstract

Here, conjugated polymer is added as third component to tune the solution viscosity, morphology, and function of small molecule (SM) based bulk-heterojunction (BHJ) solar cells, which are fabricated using blade coating. Novel information about the effect of blade coating speed on the nanoscale morphology and function of ternary blend solar cells is provided. The crystal sizes increase with an increase of coating speed for both binary and ternary blends, while the addition of the third component tends to favor smaller SM crystal grains and improves the connectivity of SM crystals. Small angle neutron scattering experiments provide the first clear experimental evidence that the addition of the third component would significantly impact the fullerene phase separation, which is crucial for bimolecular recombination and charge transport. It shows that for both binary and ternary blends, the concentration and sizes of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) aggregates increase with an increase of coating speed, while addition of third component does not affect the volume fraction of PCBM aggregates but impacts the size of PCBM aggregates. It is demonstrated that the judicious selection of blade coating speed and addition of conjugated polymer optimize the morphology of SM-BHJ, providing guidelines for high performance SM-BHJs from roll-to-roll production.

Large‐Area Blade‐Coated Solar Cells: Advances and Perspectives

“…Wu et al found that the addition of the third component can improve the morphology of BHJ layer, which was proved by a small angle neutron scattering experiment, leading to improved charge transport and device performance. [75] Zhang et al found that bladecoating can enhance the crystallinity of materials. [33] To better understand the impact of blading on films, a series of study are devoted to the observation of the film morphology The charge recombination path in the module.…”

A solution-derived bismuth aluminum gallium tin oxide film constructed by a brush coating method for spontaneous liquid crystal alignment

“…It is ecofriendly, requires low-temperature processing, and has highly reliable characteristics that are needed for next-generation technologies. Solution processing includes various coating methods, such as bar coating, 16 dip coating, 17 blade coating, 18 and brush coating. [19][20][21] In particular, the brush coating method has the distinct property of adjusting the surface orientation of the molecules during the coating process using the shear stress from the solution affected by the brush hair movements.…”

Shear Induced TiO2 Nano Structure Using Brush-Coating for Liquid Crystal Alignment

“…[10,11]. Various solution processes, including spin-coating [12], dip-coating [13], blade coating [14], and brush-coating [15,16], have been developed for advanced performance of the devices. For example, the desirable performance of optics and electronics devices can be achieved by producing high-quality polymer films or quantum dot deposition by adopting various solution coating techniques [17][18][19].…”