  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.
