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
My collaborator Myrta Grüning gave a very interesting talk about the role of excitons in non-linear optical properties of 2D materials at the OSI 2017 conference. She discusses both second and third harmonic generation in low dimensional nanostructures. Slides of her talk are available here .
Together with Myrta Gruning we just submitted a new paper on second harmonic generation(SHG) in two-dimensional materials, h-BN and MoS2. We calculated the SHG using a real-time approach that we recently developed. We included both local field effects and electron-hole interaction at the level of screened exchange , without any additional approximation. Our approch is… Read More