Single-Layered Hittorf’s Phosphorus: A Wide-Bandgap High Mobility 2D Material

We
propose here a two-dimensional material based on a single layer of
violet or Hittorf’s phosphorus. Using first-principles density
functional theory, we find it to be energetically very stable, comparable
to other previously proposed single-layered phosphorus structures.
It requires only a small energetic cost of approximately 0.04 eV/atom
to be created from its bulk structure, Hittorf’s phosphorus,
or a binding energy of 0.3–0.4 J/m2 per layer, suggesting
the possibility of exfoliation in experiments. We find single-layered
Hittorf’s phosphorus to be a wide band gap semiconductor with
a direct band gap of approximately 2.5 eV, and our calculations show
it is expected to have a high and highly anisotropic hole mobility
with an upper bound lying between 3000–7000 cm2 V–1 s–1. These combined properties
make single-layered Hittorf’s phosphorus a very good candidate
for future applications in a wide variety of technologies, in particular
for high frequency electronics, and optoelectronic devices operating
in the low wavelength blue color range.