The effect of multilayer dielectrics on electrical characteristics of thin film capacitors for high energy density application

Abstract

Hydrogenated diamond-like carbon and aluminum oxide thin films were used in combination to fabricate capacitors in order to investigate the effect of multiple dielectrics on dielectric constant, breakdown strength, and energy density. It was found that capacitors made by combining the two materials exhibited significantly higher breakdown strength and energy density than capacitors made with either dielectric material alone. In addition, the model for calculating the combined dielectric constant for multiple dielectrics was validated. The highest energy density (U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</sub> = 5.2 J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) capacitor made for this investigation had a breakdown strength of 5.3 MV/cm and an effective dielectric constant of 5.3.