Conditions for the occurrence of Coulomb blockade in phosphorene quantum dots at room temperature

TL;DR

This study investigates how substrate dielectric properties, dot size, and edge passivation influence Coulomb blockade in phosphorene quantum dots at room temperature, revealing conditions for its occurrence relevant for device applications.

Contribution

It identifies the specific substrate dielectric constants and dot sizes that enable Coulomb blockade in phosphorene quantum dots, considering edge passivation effects.

Findings

Coulomb blockade occurs in dots larger than 10 nm at low dielectric constants (<4).

Higher dielectric constants require smaller dots for Coulomb blockade.

Edge passivation influences the size and dielectric conditions for Coulomb blockade.

Abstract

We study the addition energy spectra of phosphorene quantum dots focusing on the role of dot size, edges passivation, number of layers and dielectric constant of the substrate where the dots are deposited. We show that for sufficiently low dielectric constants ($\varepsilon_{sub} < 4$), Coulomb blockade can be observed in dot sizes larger than 10 nm, for both passivated and unpassivated edges. For higher dielectric constants (up to $\varepsilon_{sub} = 30$), Coulomb blockade demands smaller dot sizes, but this depends whether the edges are passivated or not. This dramatic role played by the substrate is expected to impact on the development of application based on phosphorene quantum dots.