New Modeling for Thermionic Emission in Ideal Graphene/n-Si Schottky Solar Cells

Progress in chemically vapor deposited graphene layers on semiconductors (Si) offers new avenues for graphene based Schottky contact solar cells. Direct CVD graphene on silicon forms intimate (ideal) Schottky contact solar cells. Under illumination, thermally excited carriers from the majority and the graphene side regions may overcome the contact barrier and generate non-zero current through the junction. We propose a new model for thermionic currents in Graphene/n-Si Schottky solar cells, and predict direct dependence on T-3/2 instead of T-2 through a new Richardson constant A** that includes the thickness of the graphene layer, the contact barrier and the electronic Fermi velocity through graphene's linear density of states. Based on this, we derive explicit V-oc and J(sc) for such solar cells.