Field-modulated thermopower in $SrTiO3$-based field-effect transistors with amorphous $12CaO⋅7Al2O3$ glass gate insulator

We report transistor characteristics and field-modulated thermopower $(S)$ for single crystal $SrTiO3$-based field-effect transistors (FETs). We use 150-nm-thick amorphous $12CaO⋅7Al2O3$ glass as the gate insulator of the $SrTiO3$-FET. The resulting $SrTiO3$-FET exhibits excellent transistor characteristics at room temperature: on-to-off current ratio greater than $106$⁠, threshold gate voltage of $+1.1V$⁠, subthreshold swing of approximately $0.3Vdecade−1$⁠, and effective mobility of $2cm2V−1s−1$⁠. The field-modulated $S$-value of the $SrTiO3$-FET varied from −900 to $−580μVK−1$ with electric fields of up to $2MVcm−1$⁠, demonstrating the effectiveness of the FET structure for the exploration of thermoelectric materials.