High-Mobility Pentacene-Based Thin-Film Transistors With Synthesized Strontium Zirconate Nickelate Gate Insulators

Strontium zirconate nickelate [(SZN); Sr0.69Ni0.47Zr0.085O3.75] was synthesized through a sol–gel method by adding nickel (II) acetylacetone instead of titanium isopropoxide, which can effectively make thin films smoother and further act as gate insulators applied in pentacene-based thin-film transistors. Sol–gel SZN thin films were investigated by X-ray photoelectron spectroscopy and atomic force microscopy to confirm the chemical composition and smooth surface roughness, and the latter property was found to be compatible for pentacene thin film growth. Thus, the electrical characteristics of pentacene-based transistors exhibited a high mobility of 10.04 ${\rm cm}^{2}~{\rm V}^{-1}{\rm s}^{-1}$ low threshold voltage of ${-}{\rm 1.51}~{\rm V}$,, and low subthreshold swing slope of 350 mV/decade. To realize high mobility mechanisms, intermolecular coupling and reorganization energy of pentacene thin films were introduced. Another purpose of this introduction was to evaluate the higher hopping rate of carriers between the adjacent pentacene molecules on SZN derived from the March–Hush equation than other high- $\kappa$ traditional sol–gel insulators.