Fully transparent flexible tin-doped zinc oxide thin film transistors fabricated on plastic substrate

In this work, we have successfully fabricated bottom gate fully transparent tin-doped zinc oxide thin film transistors (TZO TFTs) fabricated on flexible plastic substrate at low temperature by RF magnetron sputtering. The effect of O₂/Ar gas flow ratio during channel deposition on the electrical properties of TZO TFTs was investigated, and we found that the O₂/Ar gas flow ratio have a great influence on the electrical properties. TZO TFTs on flexible substrate has very nice electrical characteristics with a low off-state current (I_off) of 3 pA, a high on/off current ratio of 2 × 10⁷, a high saturation mobility (μ_sat) of 66.7 cm²/V•s, a steep subthreshold slope (SS) of 333 mV/decade and a threshold voltage (V_th) of 1.2 V. Root-Mean-Square (RMS) roughness of TZO thin film is about 0.52 nm. The transmittance of TZO thin film is about 98%. These results highlight that the excellent device performance can be realized in TZO film and TZO TFT can be a promising candidate for flexible displays.