Germanene

Calculating the complex dielectric function for optical interband transitions we show that the two-dimensional crystals silicene and germanene possess the same low-frequency absorbance as graphene.

We present first-principles studies of the optical absorbance of the group IV honeycomb crystals graphene, silicene, germanene, and tinene.

After the successful synthesis of silicene in 2012, which was followed by a surge of studies on elemental, novel two-dimensional (2D) materials beyond graphene, a daunting quest was to obtain germanene, the germanium-based analogue of graphene, already predicted to possibly exist in 2009.