Low-temperature combustion synthesis and UV treatment processed p-type Li:NiOx active semiconductors for high-performance electronics

摘要

Solution-processed thin film transistors (TFTs) in the next generation of large-area flexible electrics not only need oxide semiconductors with high performance but also require them with low-temperature processability. To meet these requirements, we developed a low-temperature method, that is, combining solution combustion synthesis and deep-ultraviolet irradiation to prepare p-type Li-doped NiOx (Li:NiOx) thin films at 150 degrees C. The incorporation of Li into the NiOx matrix significantly improves p-type conductivity of NiOx because the Fermi level (E-F) shifts toward the valence band maximum. To confirm the possible application of Li:NiOx as the channel layer in TFTs, Li:NiOx/ZrO2/ITO was fabricated on each of rigid glass and flexible PET substrates. This is the first report of application of Li:NiOx semiconductor in TFT devices. The field-effect mobility, I-on/I-off and subthreshold swing for rigid and flexible Li-5%:NiOx TFTs are 1.69 and 1.41 cm(2) V-1 s(-1), 8 x 10(6) and 10(5), 0.21 and 0.54 V dec(-1), respectively. Furthermore, the counterclockwise hysteresis of transfer curves is negligible (0.1 V). Thus, the high-performance and cost-effective electronics with low fabrication temperature will definitely contribute to future large-scale flexible and wearable electronics.