Number-of-layer, pressure, and temperature resolved bond-phonon-photon cooperative relaxation of layered black phosphorus.

We systematically examined the effects of number-of-layer, pressure, and temperature on the bond length and energy, Debye temperature, atomic cohesive energy, and binding energy density for layered black phosphorus using bond-phonon-photon spectrometric methods. We clarified the following: (1) atomic under-coordination shortens and stiffens the PP bond, which raises the B2g and Ag2 phonon frequency and widens the bandgap, (2) bond thermal elongation and weakening soften all phonon modes, and (3) bond mechanical compression has the opposite effect of heating on phonon frequency relaxation. The phonon and photon energy depends on the bond length and energy, which determines the relevant elasticity and thermal stability of layered structure. More broadly, the approaches and findings of this work provide both insight into and efficient tools for further exploration of unusual behaviors of other two-dimensional substance. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]