Negative Capacitance in Amorphous Semiconductor Chalcogenide Thin Films

Certain amorphous materials exhibit rapid electrical switching. The variation in their capacitance was evaluated as a function of temperature and electric field in the high-resistance state. The zero-field capacitance follows a Curie-Weiss law above room temperature. At low temperatures, and at fields near the threshold of switching for higher temperatures, the open-circuit incremental ac capacitance becomes negative.