Metastable state involved resonant tunneling through single InAs/GaAs quantum dot

TL;DR

This paper demonstrates resonant tunneling through a metastable state in single InAs/GaAs quantum dots at room temperature, enabling potential single-electron devices for photocurrent amplification.

Contribution

It introduces a novel scheme for resonant tunneling via metastable states in quantum dots under illumination, verified through transport studies at room temperature.

Findings

Resonant tunneling observed at room temperature.

Tunneling current amplitude depends on barrier and hole concentration.

Steady tunneling current despite variation in quantum dot height.

Abstract

A scheme of resonant tunneling through the metastable state of semiconductor quantum dot is presented and implemented in the transport study of freestanding InAs quantum dots grown on GaAs(001) under illumination using conductive atomic force microscopy. The metastable state is achieved by capturing one photoexcited Fermi hole in the valence energy level of InAs quantum dot. Resonant tunneling through single quantum dot can be observed at room temperature due to the existence of metastable state. The amplitude of tunneling current depends on the barrier arrangement and the concentration of photoexcited holes around the quantum dot, but is found steady when the height of dot varies from 1.8 to 9.9 nm, which are in good agreement with the proposed model. The experiment demonstrates a solution of room temperature operated single electron device to amplify the photocurrent by the singularity of resonant tunneling in epitaxial quantum dot.