Dr. Deniz Cakir
Department of Physics,
University of Antwerp
Electronic and optical properties of monolayer and few-layer black phosphorus: A DFT Perspective
Phosphorene, or monolayer black phosphorus, is a new 2D layered material with high carrier mobility and direct semiconducting band gap. One of the most interesting characters of phosphorene is highly anisotropic electronic and optical properties due to its anisotropic puckered atomic structure, making it a very promising material for electronics and optoelectronics applications.
In this talk, I will discuss the effect of strain and staking type on the electronic and optical properties of monolayer and few-layer black phosphorus by the help of density functional theory calculations. We find that the optical properties (i.e. absorption spectrum and exciton binding energy) and the electronic properties (i.e. band structure and effective mass) are highly anisotropic and strongly depend on the amount of applied strain in monolayer black phosphorus and type of staking in few-layer black phosphorus. Due to reduced dimensionality and weak screening, the calculated exciton binding energies are quite large and found to be in the range of 0.3-0.8 eV depending on applied strain and staking type. In addition, strain and type of staking are able to tune the electronic band gap and optical gap of black phosphorus by 1.5 eV. Such a wide tuning ability of the electronic band gap and optical gap allows us to design novel optoelectronic devices that capture a broad range of solar spectrum.