Figure 4
From: Systematic competition between strain and electric field stimuli in tuning EELS of phosphorene

Left side, general interband optical transitions and excitations between different bonding and antibonding electronic orbitals in phosphorene. Right side, electron energy loss spectrum of “pristine” monolayer BP along both AC and ZZ directions inside the infrared (IR), visible (VIS), and ultraviolet (UV) regions of the electromagnetic spectrum.