Coulomb blockade and quantum confinement in field electron emission from heterostructured nanotips

TL;DR

This paper reveals a novel field electron emission mechanism involving Coulomb blockade and quantum confinement in heterostructured nanotips, supported by experiments and numerical simulations, advancing understanding of electron emission at the nanoscale.

Contribution

It introduces a new FE mechanism combining Coulomb blockade and quantum confinement effects in heterostructured nanotips, supported by experimental and theoretical analysis.

Findings

Multiple peaks in energy distributions due to quantum confinement.

Modified Coulomb staircase observed in I-V characteristics.

Experimental results align with numerical Coulomb blockade models.

Abstract

A new field electron emission (FE) mechanism, which includes Coulomb blockade and quantum confinement effects, is revealed for heterostructured emitters composed of quantum dots and nanowires self-assembled at diamond nanotips. The total energy distributions of the emitted electrons show multiple peaks attributed to the discrete electronic states of the quantum-confined emitter with the corresponding energy levels oscillating as a function of the applied voltage due to the Coulomb blockade. The FE current-voltage characteristics exhibit a modified Coulomb staircase with additional steps becoming more pronounced with increasing voltage. The experimentally observed behavior is consistent with numerical simulations based on the model of Coulomb blockade in quantum dots in combination with the theory of FE from sharp tips.