Praseodymium-Doped In-Sn-Zn-O TFTs With Effective Improvement of Negative-Bias Illumination Stress Stability

In this work, amorphous praseodymium-doped In-Sn-Zn-O (ITZO-Pr) thin-film transistors (TFTs) were fabricated with improved negative-bias illumination stress (NBIS) stability under different radio frequency (RF) magnetron sputtering powers. The optimized ITZO-Pr TFTs presented field effect mobility (
$\boldsymbol {\mu }_{\text{FE}}$
) of 20.9 cm
$^{2}\cdot {}\text{V}^{-1}\cdot {}\text{s}$
⁻¹
, steep subthreshold (SS) of 0.27 V/dec, and small threshold voltage shift (
${\Delta } {V}_{\text{th}} = -2.12$
V) under NBIS (−20 V, 3600 s). All Pr-doped devices exhibited a reduction in light responsivity of more than one order of magnitude compared with ITZO TFTs. Moreover, after Pr doping, relaxation processes of photoelectrons changed and then the activation energy (
${E}_{\text{a}}$
) of light-induced electrons relaxation decreased, which enhanced the NBIS stability of ITZO TFTs effectively.