Electro-absorption of silicene and bilayer graphene quantum dots
Journal of Applied Physics
American Institute of Physics (AIP)
We study numerically the optical properties of low-buckled silicene and AB-stacked bilayer graphene quantum dots with zigzag edges subjected to an external electric field, which is normal to their surface. Within the nearest-neighbor approximation of the tight-binding model the optical absorption spectrum is calculated for quantum dots of triangular and hexagonal shapes. In triangular silicene clusters a rich and widely tunable infrared absorption peak structure originates from transitions involving zero energy states. The edge of absorption in silicene quantum dots undergoes red shift in the external electric field for triangular clusters, whereas blue shift takes place for hexagonal ones. In small clusters of bilayer graphene the edge of absorption undergoes blue/red shift for triangular/hexagonal geometry.
This work was supported by the EU FP7 ITN NOTEDEV (Grant No. FP7-607521); EU H2020 RISE project CoExAN (Grant No. H2020-644076); FP7 IRSES projects CANTOR (Grant No. FP7-612285), QOCaN (Grant No FP7-316432), and InterNoM (Grant No FP7-612624); Graphene Flagship (Grant No. 604391); and the Egyptian mission sector.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.
Vol 120, 014304 (2016)