Herein, we report on the design and synthesis of an N-annulated perylene butyl tetraester (PTEN-H) for use in alcohol processed semiconducting films. PTEN-H was contrasted with the known N-annulated perylene diimide (PDIN-H) where the former has ring-opened imide positions which in turn lowers the electron affinity (i.e., rendering hole transporting) and improves polar green solvent solubility. PTEN-H can be solubilized in 1-butanol up to 10 mg/mL with gentle heating and can be spin-cast or slot-die coated to form uniform thin films on glass and/or plastic substrates. Organic field-effect transistors (OFETs) were fabricated using PTEN-H in the active material layer which was deposited from solution using 1-butanol as the solvent. While hole mobilities were achieved (0.39 x 10-4 cm2/Vs), blending the molecular material with a previously reported green solvent processable semiconducting polymer, IIG20-OH, was done to boost performance. This led to increased mobilities for not only the native molecular PTEN-H material, but for the native IIG20-OH polymer as well. Furthermore, a blend of PTEN-H and IIG20-OH were slot-die coated onto a polyethylene terephthalate (PET) substrate giving uniform thin films suitable for large area device fabrication.

Design of organic π-conjugated semiconducting materials is an exciting avenue of research that has already found promising applications in a wide variety of fields, ranging from stretchable electronics to bioimaging and theranostics. With favorable optoelectronic and thermomechanical properties, these materials and related devices can provide a complementary alternative to commercial silicon-based electronics. One of the most important features of organic semiconductors is their ability to be solution processed, allowing access to a wide variety of printing and solution deposition techniques inaccessible to silicon. However, the solution processability of these materials also poses challenges for the development of multilayer electronics due to potential problems such as swelling, film deformation and interfacial mixing that can occur upon successive solution deposition. Use of orthogonal (noncompatible) solvents and solvent-free deposition methods have been extensively investigated as solutions to this challenge, although the applicability of these approaches is limited by the chemical properties of the materials used. Another approach to address this problem is to focus on the materials rather than deposition methods. Through rational design, functional groups can be used to create triggered solvent resistance through covalent or dynamic intermolecular bonds. Design strategies include the incorporation of photo- and thermally cleavable functional groups in the materials, or the use of chemical additives/reagents to significantly alter the solubility of π-conjugated materials and afford solvent-resistant thin films. This spotlight article presents recent progress toward solvent-resistant organic materials with an emphasis on their use in electronic applications. Recent and key developments will be discussed from a personal perspective, providing an overview of the different approaches used to achieve solvent-resistant semiconducting materials toward the fabrication of advanced, multilayer organic electronics.