Thin-film transistors (TFTs) matured later than silicon integrated circuits, but in the past 15 years the technology has grown into a huge industry based on display applications, with amorphous and polycrystalline silicon as the incumbent technology. Recently, an intense search has developed for new materials and new fabrication techniques that can improve the performance, lower manufacturing cost, and enable new functionality. There are now many new options - organic semiconductor (OSCs), metal oxides, nanowires, printing technology as well as thin-film silicon materials with new properties. All of the new materials have something to offer but none is entirely without technical problems.