Room-Temperature Processing of Printed Oxide FETs Using Ultraviolet Photonic Curing

Oxide semiconductors are highly suitable materials for solution-processed/printed electronics (PE); the growing interest in them can be related to their excellent intrinsic properties, such as high mobility, optical transparency, thermal and environmental stability, and so on. However, high process temperatures remain as the foremost challenge that may limit the compatibility of printed oxide electronics to inexpensive flexible substrates. Here, the possibility of using photonic curing methods to lower the process temperature is investigated, even down to room temperature (RT). Two distinct ultraviolet (UV) curing techniques, involving UV–visible light pulses and continuous-wave UV lasers are exercised and compared. Combining UV curing with oxide nanoparticulate channel layer and electrolytic gate insulators, it is demonstrated that high performance field-effect transistors (FETs) with device mobility as high as 12 cm2 V−1 s−1 can be processed entirely at room temperature and realized on plastic substrates. The fabrication steps include printing of a heavily stabilized semiconducting nanoparticulate channel layer, followed by decomposition and removal of the semi-insulating polymer ligands using UV-photon energies. The curing process is found to be fast and high-throughput manufacturing technique compatible. At the same time, the energy requirement to remove the polymer stabilizers is insignificant, thereby ensuring no temperature rise of the parent substrates.