I-V characteristics of the contact interface in a semiconductive BaTiO3-In composite particle

The authors previously fabricated semiconductive BaTiO3-In composite particles. The aggregate could be used as a new positive temperature coefficients (PTC) material, which could be used in arbitrary shapes, differing from the conventional rigid PTC materials. In the composite particle, the interface between the semiconductive BaTiO3 particles and indium particles plays an important role. In this work I-V characteristics of the interface are investigated in detail. The conclusions obtained in this research are as follows. (1) The existence of indium particles at the interface between two semiconductive BaTiO3 particles lowered the electric resistance markedly. This effect was ascribed to the good plasticity and a low value of the work function of indium. (2) In-Ga eutectic liquid alloy and physically vapor-deposited indium film satisfied Ohmʹs law and did not form a Schottky barrier at the interface with the semiconductive BaTiO3 material. (3) Physically vapor-deposited gold film formed a high electric resistance at the interface with the semiconductive BaTiO3 material. This high resistance might be caused by a Schottky barrier.