Spray Deposition for Solvent Annealing of Hybrid Poly(3,4-Ethylenedioxythiophene) Polystyrene Sulfonate Cellulose Silver Nanowire Composite Electrodes Using a Roll-to-Roll Coater

Spray deposition is a rapid and facile technique for coating surfaces on a large scale. The quality of these coatings can be improved via post-treatment. One example is solvent annealing, a well-known strategy to enhance the conductivity of polymeric electrode materials using organic solvents. Herein, the annealing of sprayed poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-based electrodes via solvent spray deposition in a single roll-to-roll setup is reported. The annealing rates of three solvents, namely dimethyl sulfoxide (DMSO), isopropanol (IPA), and methanol (MeOH), depending on the spray time and sprayed volume, are evaluated and correlated with structural changes. The results show that the applied method reduces the sheet resistance (R_s) of pure PEDOT:PSS films by 82% using DMSO and of cellulose-based silver nanowire-PEDOT:PSS electrodes by 50% using MeOH. This approach allows for the facile and effective combination of fabrication and quality enhancement of sprayed, conductive polymer films using only one piece of equipment. This approach makes the overall production process of organic electrodes faster and cheaper and therefore the usage of sustainable materials and fabrication methods more attractive for the industry.