wileyonlinelibrary.comTFPV is the use of toxic and halogenated solvents to dissolve the photoactive blend of materials. Furthermore, the deposition technique typically used for lab-scale solution-processed TFPV, spin coating, is not transferable to an industrial production setting. [4][5][6] Transitioning to nonhalogenated solvents affords a more environmentally friendly and less toxic approach, while blade coating offers a precise and reliable linear deposition technique that can be scaled from lab to fab. [7][8][9][10][11][12][13][14] Blade coating is a large area applicable, linear deposition technique used in rollto-roll and sheet-to-sheet coating industries. [ 4,[15][16][17] A blade, in near-contact with the underlying substrate, spreads a droplet of ink over a substrate, optimally resulting in a smooth and uniform coating, free of pinholes and ribbing. Blade height, blade speed, and substrate temperature are some of the key intrinsic deposition parameters, while ink composition is a determining factor for deposition results, solubility, and wettability.The Hansen solubility parameters (HSP) describe the properties of solutes, solvents, and solvent systems, and enable a theoretical description of the solubility of materials. [ 18,19 ] Three parameters represent the polar, hydrogen, and dispersion components of interaction for both materials and solvents, where similar-valued materials are more likely to dissolve each other than dissimilar-valued materials. The HSP space of solubility for a solute may be approximated by an ellipsoidal volume where solvent systems with a combined parameter value within this volume dissolve the solute, while those systems with a value outside the ellipsoid do not dissolve the solute. The HSP for a material are determined by measuring the material solubility in a variety of solvents with known solubility parameters and by fi tting an ellipsoid to the HSP for equal solute concentrations. Thus, the HSP are dependent on the threshold of solubility desired, shifting with the concentration limits of the foreseen application. This selection method has been described in several studies for the determination of solvents for organic photovoltaic materials. [ 7,12,20,21 ] Nonhalogenated solvents are one step toward industrially viable printing of solution-processed TFPV. [7][8][9][10][11][12][13][14] Several studies have reported potential replacements for halogenated solvents that are commonly used in OPV fabrication; however, With lab-scale solution-processed thin fi lm photovoltaic (TFPV) devices attaining market relevant effi ciencies, the demand for environmentally friendly and scalable deposition techniques is increasing. Replacing toxic halogenated solvents is a priority for the industrialization of solution-processed TFPV. In this work, a generalized fi ve-step process is presented for fabricating high-performance devices from nonhalogenated inks. Resulting from this process, several new solvent systems are introduced based on thiophene, tetralin, 1,2,4-trimethylbenzene, o -xylene...
