Electrically induced colossal capacitance enhancement in LaAlO3/SrTiO3 heterostructures

Abstract

The demonstration of a tunable conductivity for the LaAlO3/SrTiO3 interfaces by field effect drew significant attention to the development of oxide-based electronics. The increase in the gate capacitance of the LaAlO3/SrTiO3-based field-effect transistor is particularly important for conductivity modulation and the development of logic devices. Here, we demonstrate the annihilation of quantum capacitance and colossal capacitance enhancement (approximately 1000%) in LaAlO3/SrTiO3 heterostructures by DC gate voltage at room temperature, which we attribute to the motion of oxygen vacancies through the thickness of the LaAlO3 layer. These capacitor devices will provide a platform for the further development and application of metal-oxide-semiconductor transistors.