Improvement of solution-processed Zn-Sn-O active-layer thin film transistors by novel high valence Mo doping

In this letter, the performance of Zn-Sn-O (ZTO) thin film transistors (TFTs) has been greatly improved by Mo doping as an oxygen vacancy to control the residual electrons. The results show that the TFT with 3 at% Mo doping exhibits the best electrical characteristics with a high saturation mobility of 26.53 cm² V^-1 s^-1, a threshold voltage of 0.18 V, a subthreshold swing of 0.32 V dec^-1 and a large switching ratio of 2 × 10⁶. The saturation mobility and switching ratio of Mo-doped Zn-Sn-O (MZTO, 3 at%) TFTs improved almost five and two orders of magnitude compared with ZTO TFTs, respectively. Therefore, the MZTO TFT has much potential for future electrical applications with its excellent properties.