Bias-stress-stable sub-1.5V oxide thin-film transistors via synergistic composition of sol-gel quaternary high- k oxide dielectrics

A rising demand in reliable, energy -efficient, and large -area electronics, particularly in the realm of sol-gel oxide thin-film transistors (TFTs), has steered research focus away from semiconductor towards dielectrics. However, achieving both bias stability and low -voltage operation remains a significant hurdle. While typical oxide TFTs employ high -dielectric -constant (high - k ) dielectrics with lowered film thickness to acquire low -voltage operation, they inevitably suffer from undesired defects at both bulk and interfacial trap sites in dielectric layer. In this study, bias -stress -stable all solution -processed oxide TFTs were demonstrated with operation voltage under 1.5 V via sol-gel quaternary high - k oxide dielectric (Al-Hf-Zr-O, AHZO). In-depth understanding of their individual contributions to dielectric performance leads to the acquisition of optimized composition ratios of AHZO with amorphous feature and outstanding dielectric performance, marked by dielectric constant ( k ) over 11, leakage current density ( J leak ) below 10 -5.5 A cm -2 , and sturdy breakdown strength ( E B ) exceeding 5 MV cm -1 . By integrating the AHZO with In-Ga-Zn-O (IGZO) layer, we achieved sub 1.5 V TFTs while maintaining excellent bias stability with threshold voltage ( V TH ) shift lower than 0.20 V for 3600 s. Our findings offer a detailed insight into the realm of multi -component oxide dielectrics, paving the way for miniaturization and reliability in functional devices and sensors.