Fully printed organic thin-film transistors: pathways to scalable, high-performance flexible electronics

The emergence of large-area electronics for the Internet of Things (IoT) necessitates the development of next-generation, lightweight, flexible, and energy-efficient devices. These devices demand high-throughput, low-cost production of reliable transistors and circuits seamlessly integrated into flexible substrates. The processability of organic semiconductor materials enables printing-based fabrication technologies, offering significant advantages over conventional semiconductors in terms of ease of processing, compatibility with flexible substrates, cost-effectiveness, and scalability. Despite these advantages, reports on fully printed organic thin-film transistors (OTFTs) and their integrated circuits remain limited, and the pathway from partially printed to fully printed organic devices is not yet fully established. This review provides a comprehensive analysis of various printing techniques and an overview of functional inks used in OTFT fabrication. We further present various methodologies from a chemistry perspective for optimizing channels, contacts, and dielectric interfaces to overcome performance limitations. Recent advancements in fully printed OTFTs and circuits are highlighted, underscoring the potential of these devices in flexible electronics. Finally, critical challenges-such as achieving high electrical performance, improving printing resolution, and enhancing manufacturing efficiency-are debated, with a focus on how chemical innovations in material synthesis, interface engineering, and process chemistry will facilitate progress. Overcoming these hurdles through chemical optimization will accelerate the adoption of printed organic electronics in next-generation IoT applications.