Lingling Huang

High-Performance Al–Sn–Zn–O Thin-Film Transistor With a Quasi-Double-Channel Structure

We successfully fabricated high-performance Al-Sn-Zn-O thin-film transistors (ATZO TFTs) with a quasidouble-channel (QDC) structure on glass by radio-frequency magnetron sputtering. The bilayer ATZO films are fabricated with different oxygen partial pressures during the sputtering process. The structure of the top ATZO layer is optimized to improve OFF-state performances. With this QDC structure, the ATZO TFT demonstrates excellent electrical performances, including a low OFF-state current of 840 fA, an ON/OFF current ratio of 1.08 × 109, a steep threshold swing of 0.16 V/decade, a superior saturation mobility of 108.28 cm2V-1s-1, and a threshold voltage of 2.09 V.

Flexible nickel-doped zinc oxide thin-film transistors fabricated on plastic substrates at low temperature

High-performance nickel (Ni)-doped zinc oxide thin-film transistors (NZO TFTs) have been successfully fabricated on transparent flexible plastic substrates at a low temperature. The effect of different oxygen partial pressures during channel deposition on the electrical properties of NZO TFTs was studied to improve the device performance. We found that the oxygen partial pressure during channel deposition has a significant influence on the performance of NZO TFTs. Finally, it was demonstrated that a NZO film with 100% Ar sputtering gas during channel deposition exhibited the best electrical properties, with a drain current on/off ratio of 108, a positive threshold voltage of 2.59 V, a subthreshold swing of 233 mV/decade, and a saturation mobility of 118.9 cm2V−1s−1. The results show that Ni-doped ZnO is a promising candidate for flexible fully transparent displays.

Effects of various oxygen partial pressures on Ti-doped ZnO thin film transistors fabricated on flexible plastic substrate

By applying a novel active layer of titanium zinc oxide (TiZO), we have successfully fabricated fully transparent thin-film transistors (TFTs) with a bottom gate structure fabricated on a flexible plastic substrate at low temperatures. The effects of various oxygen partial pressures during channel deposition were studied to improve the device performance. We found that the oxygen partial pressure during channel deposition has a significant impact on the performance of TiZO TFTs, and that the TFT developed under 10% oxygen partial pressure exhibits superior performance with a low threshold voltage (V th) of 2.37 V, a high saturation mobility (μsat) of 125.4 cm2 V−1 s−1, a steep subthreshold swing (SS) of 195 mV/decade and a high I on/I off ratio of 3.05 × 108. These results suggest that TiZO thin films are promising for high-performance fully transparent flexible TFTs and displays.

Fully-transparent Mo-doped ZnO TFTs fabricated in different oxygen partial pressure at low temperature

Fully-transparent Mo-doped ZnO (MZO) thin film transistors (TFTs) have been successfully fabricated on glass substrate by radio frequency Magnetron Sputtering at room temperature and its characteristics have been studied in different oxygen partial pressure. The results show that the MZO TFTs which were deposited at low oxygen partial pressure (10%) have excellent performance such as subthreshold swing of 388 mV/decade, the saturation mobility of 5.8 cm2/V·s, the threshold voltage of 3.97 V, the Ioff value of 5×10-12 A, and the on/off current ratio of 2.4×107. To identify properties of the film formed at oxygen partial pressure of 10%, X-ray diffraction, scan electron microscopy, and transmittance were used to investigate the microstructure of the films. All conclusions suggest that MZO TFTs will become a promising candidate for TFT-LCD.