Negative capacitance of native oxide films on (0001) InSe fracture surfaces

A negative capacitance has been found at low frequencies (1 × 10 5 to 3.7 × 10 7 Hz) in native oxide films grown in air on InSe(0001) fracture surfaces. The films have the form of a dielectric Se 2 O 5 matrix containing indium metal nanoinclusions. Resistivity and capacitance measurements at frequencies from 100 Hz to 37 MHz have been used to study the polarization mechanisms for the native oxide films in In/native oxide/InSe structures. The results indicate that a negative capacitance (inductive impedance) of native oxide films may be due to carrier capture at traps located at the many metal—dielectric interfaces.