Carrier-suppressing effect of Mg in solution-processed Zn-Sn-O thin-film transistors

摘要

We investigated the effect of Mg addition on solution-processed Zn-Sn-O (ZTO) thin-film transistors (TFTs). Because Mg affects the optical bandgap and the metal-oxygen bond in ZTO films, the carrier concentration of Mg-Zn-Sn-O (MZTO) films was suppressed by Mg. As the molar ratio of Mg increased in the MZTO TFTs annealed at 500°C, the onoff ratio increased, and the subthreshold gate swing (S.S) decreased considerably. As a result, the MZTO TFT showed a saturation mobility of 1.00 cm ~2V s, an S.S of 0.92 Vdecade, a threshold voltage (V _(th)) of 6.60 V, and an onoff ratio of 3.15 ×10 ~6.