Category Archives: luminescence

A squashed and squeezed h-BN

In this seminar I present new thoeretical and exparimental results on hexagonal-boron nitride under isotropic pressure and uni-axial strain. In particalar we focused on the changes in the optical response both absortion and emission. We show how exicton behave under these extreme conditions.The presentation can You can downloaded here: A squashed and squeezed h-BN [ODP]

Theory of phonon-assisted luminescence

In this presentation I present the theory of phonon-assisted luminescence, in terms of non-equilibrium  Green’s functions and time-dependent perturbation theory. We derived a simple formule for light emission in the limit of low excited carriers including excitonic effects and then included coupling with phonons by time-dependent perturbation theory. This approach is then applied to the… Read More

Luminescence of hexagonal boron nitride explained

Luminescence of hexagonal boron nitride (hBN) has puzzled researchers for long time. In standard solid state physics textbooks direct band gap semiconductors are considered efficient light emitters while indirect ones are regarded as inefficient. Hexagonal boron nitride seems to defy this rule. In fact hBN emits light in the ultraviolet with an efficient comparable to… Read More