Temperature-dependent collective effects for silicene, germanene and monolayer black phosphorus

TL;DR

This study numerically investigates temperature-dependent electronic properties and plasmon behavior in silicene, germanene, and black phosphorus, revealing how these properties vary with doping, temperature, and energy gaps in these emerging 2D materials.

Contribution

It provides the first detailed analysis of temperature effects on exchange, correlation energies, and plasmon splitting in silicene, germanene, and black phosphorus, expanding understanding of their collective electronic behaviors.

Findings

Energies increase with doping and decrease at higher temperatures.

Distinct plasmon branch splitting observed in puckered lattices.

Behavior varies with asymmetry gap and temperature, affecting electronic properties.

Abstract

We have calculated numerically electron exchange, correlation energies and dynamical polarization function for newly discovered silicene, germanene and black phosphorus (BP), consisting of puckered layers of elemental phosphorus atoms, broadening the range of two-dimensional (2D) materials at various temperatures. As a matter of fact, monolayer BP, produced by mechanical and liquid exfoliation techniques, has been predicted to be an insulator with a large energy splitting 1.6 eV for the quasiparticle band structure. We compare the dependence of these energies on the chemical potential, field-induced gap and the temperature and concluded that in many cases they behave qualitatively similarly, i.e., increasing with the doping, decreasing significantly at elevated temperatures, and displaying different dependence on the asymmetry gap at various temperatures. Furthermore, we used the dynamical polarizability to investigate the new "split" plasmon branches in the puckered lattices and predict a unique splitting, different from that in gapped graphene, for various energy gaps. Our results are crucial for stimulating electronic, transport and collective studies of these novel materials, as well as for enhancing silicene-based fabrication and technologies for photovoltaics and transistor devices.