Fig. 4: Open-circuit voltage and charge-transfer state energy of a planar junction solar cell.
From: Open-circuit voltage of organic solar cells: interfacial roughness makes the difference
a Model of a planar junction solar cell with a rough interface and co-deposited donor materials. Geometrical parameters of a rough interface: period, λ, width, h, and a minimal separation between the donor and acceptor molecules, δ. b Dependence of the open-circuit voltage (Voc, open symbols), and charge-transfer state energy (Ect, closed symbols) on the concentration c of ZnPc in the ZnPc:F4ZnPc and ZnPc:F\({}_{4}^{* }\)ZnPc solar cells. The experimentally measured slopes (black lines and symbols) are best reproduced for ρ = 1.
