Resonant tunneling through quantum dots in GaAs Schottky diode structures

We fabricated GaAs metal-semiconductor Schottky diodes containing InAs self -assembled quantum dots. Current transport characteristics were measured at 77 K. Current peaks and negative differential resistance had been observed under reverse bias in some diodes. The second derivatives of the current o f all diodes show clear dips. All these structures were interpreted as bein g due to the resonant tunneling through the zero-dimensional energy states of InAs quantum dots. Three bound states can be clearly observed for most o f the diodes. The energy gaps between the bound states of quantum dots were roughly estimated from the dips to be about 50-80 meV.