Resonant tunneling through energy states of InAs quantum dots in GaAs metal–semiconductor diode structures

Abstract

Direct electronic transport properties in a GaAs metal–semiconductor diode structure containing InAs self-assembled quantum dots are reported. Current peaks and negative differential resistance due to resonant tunneling through the zero-dimensional states of the InAs dots are clearly observed under reverse biases. The second derivative of the current versus voltage shows more structures at larger voltages, which are attributed to the resonant tunneling through the excited states of the quantum dots. From the peak positions in the second derivative, the energy separations between the states of the quantum dots are roughly estimated according to a simple calculation based on our experimental data.