Abnormal current increases induced under high electric fields in asymmetrical graphite-intrinsic-diamond-graphite structures fabricated with high-quality homoepitaxial chemical-vapor-deposited diamond layers

An abnormal current amplification phenomenon appearing in high-quality chemical-vapor-deposited (CVD) diamond under high electric fields is examined by measuring current-voltage and electroluminescence (EL) characteristics of an asymmetric graphite-intrinsic-diamond-graphite (G-ID-G) structure specially prepared with a high-quality homoepitaxial CVD diamond layer. The field calculations using a finite element method has shown both injections from the G layer to the ID layer and high-field-induced excitations of valence electrons in the ID layer to the conduction bands by the impact of the current.