Driven by the rapid development of novel active-matrix displays, thin-film transistors (TFTs) based on metal-oxide (MO) semiconductors have drawn great attention during recent years. N -type MO TFTs manufactured through vacuum-based processes have the advantages of higher mobility compared to the amorphous silicon TFTs, better uniformity and lower processing temperature compared to the polysilicon TFTs, and visible light transparency which is suitable for transparent electronic devices, etc. However, the fabrication cost is high owing to the expensive and complicated vacuum-based systems. In contrast, solution process has the advantages of low cost, high throughput, and easy chemical composition control. In the first part of this review, a brief introduction of solution-processed MO TFTs is given, and the main issues and challenges encountered in this field are discussed. The recent advances in channel layer engineering to obtain the state-of-the-art solution-processed MO TFTs are reviewed and summarized. Afterward, a detailed discussion of the direct patterning methods is presented, including the direct photopatterning and printing techniques. Next, the effect of gate dielectric materials and their interfaces on the performance of the resulting TFTs are surveyed. The last topic is the various applications of solution-processed MO TFTs, from novel displays to sensing, memory devices, etc. Finally, conclusions are drawn and future expectations for solution-processed MO TFTs and their applications are described.

Indium-tin-zinc-oxide (ITZO) as the channel layer grown by co-sputtering of ZnO target and ITO target in the bottom gate thin-film transistors (TFTs) is proposed in this work. The microstructure and optical properties of ITZO thin films at different annealing temperatures were analyzed. The impact of various annealing temperatures on the ITZO TFT performance characteristics was systematically investigated as well. It was found that ITZO TFT with annealing temperature of 300 °C exhibits excellent electrical performance with a high saturation field-effect mobility (μ_sat) of 27.4 cm² V⁻¹ s⁻¹, a low threshold voltage (V_th) of −0.64 V, a small subthreshold swing (SS) value of 0.23 V per decade, and the high on-off current ratio (I_on/I_off) of 1.8 × 10⁷. In addition, it also shows good output curves including gate control capabilities and good electrode contact as well as extreme atmospheric stability. As shown by photoluminescence (PL) analysis and X-ray photoelectron spectroscopy (XPS) analysis, the beneficial effects of various annealing temperatures on device performance are attributed to the reorganization of the amorphous network and the control of defect chemistry in the films. The correlation between the post-deposition thermal treatment and the characteristics of a transistor was investigated and excellent performance of the transistor was demonstrated.

A stretchable capacitive strain sensors based on vertical graphene electrodes with unique stress direction recognizing ability is demonstrated, showing potential to detect physical and physiological signals.