  We investigate the electronic and optical properties of monolayer and
stacking dependent bilayer blue phosphorus in the framework of density
functional theory (DFT) and tight-binding approximations. We extract the
hopping parameters of TB Hamiltonian for monolayer and bilayer blue phosphorus
by using the DFT results. The variation of energy band gap with applied
external electric field for two different stacks of bilayer blue phosphorus are
also shown. We examine the linear response of the systems due to the external
electromagnetic radiation in terms of the dielectric functions in the DFT
theory. The relatively large electronic band gap and possibility of exfoliation
form bulk structure due to weak interlayer coupling, make blue phosphorus an
appropriate candidate for future electronic devices.
