Transferrable, wet-chemistry-derived high-k amorphous metal oxide dielectrics for two-dimensional electronic devices.

Abstract

Two-dimensional (2D) materials hold transformative potential for next-generation electronics. The integration of high dielectric constant (k) dielectrics onto 2D semiconductors, while maintaining their pristine properties by low-defect-density interfaces, has proven challenging and become one performance bottleneck of their practical implementation. Here, we report a wet-chemistry-based method to fabricate amorphous, transferable high-k (42.9) copper calcium titanate (CCTO) thin films as high-quality, dual-function dielectrics for 2D electronic devices. The chelation-based Pechini approach guarantees uniformity in this perovskite-type complex oxide, while the transferrable feature allows its harmless integration to 2D semiconductors interfacing with a nanogap. The CCTO-gated MoS₂ devices exhibit a subthreshold swing down to 67 mV dec^-1 and an ultra-small hysteresis of ~ 1 mV/(MV cm^-1). Moreover, leveraging its visible-light active characteristics, we implement an electrically-manipulated, optically-activated nonvolatile floating gate in CCTO, enabling the reconfigurable execution of 9 basic Boolean logic in-sensor operations within a single field-effect device architecture. This advancement paves the way for the development of multifunctional, low-power 2D electronic systems by incorporating multifunctional conventional complex oxides.