The electronic and interband optical properties of vertically coupled stacked graphene
quantum dots are investigated using the tight-binding method. Both zigzag and armchair
edge configurations are taken into account. In particular, the effect of the geometrical shape
(triangular or circle-like) and, most prominently, of the angle of twisting between layers is
mainly addressed. The optical response is analyzed from the calculated imaginary part of
the dielectric function. It is found that the interband absorption threshold is highly dependent …