Poly(9-Vinylcarbazole)/Graphene Nanoheterostructure Interfaces: Ab Initio Dynamics Studies for Photovoltaic and Optoelectronic Applications

Polymer photovoltaics have great technological potential as an alternative source of electrical energy. The demand for inexpensive, renewable energy sources drives new approaches to produce low-cost polymer solar cells. In the last decade, the development of these solar cells has progressed rapidly. One of the limiting parameters of these polymer photovoltaics is the mismatch between their absorption spectrum and the terrestrial solar spectrum. Using low-band-gap polymers is a viable method to expand the absorption spectrum of solar cells and increase their efficiency. We report first-principles calculations on the binding of Poly(9-vinylcarbazole), PVK, to graphene. Considering the different relative orientations of the subsystems, our calculations predict reasonable binding energies, demonstrating interactions between the polymer and graphene. The band gap value we have calculated in this work is low enough to make the nanoheterostructure exceedingly promising for photovoltaic applications.