SPACE-CHARGE-LIMITED CURRENTS IN HETEROEPITAXIAL FILMS OF SILICON GROWN ON SAPPHIRE

Abstract

Experimental results are presented on current-voltage relations in heteroepitaxial silicon films grown on sapphire. Above a threshold voltage a current is observed which is proportional to the square of the applied voltage, but inversely proportional to the square of the distance. It is interpreted as space-charge-limited current. The square law dependence with distance is a deviation from the Mott-Gurney law of space-charge-limited current in solids, which predicts I ∝ L−3, and is a consequence of the electrode configuration.