Simulation of Ternary Organic Solar Cells to Study the Effects of Morphology and Material Properties on Power Output

Ternary organic solar cells were simulated as a 3D grid of resistors and photodiodes to study how a secondary acceptor as a third material affects the overall blend to optimize for power output. The voltage at zero current, VOC, of the donor and secondary acceptor interfaces should be at least that of the primary system. When the thickness and secondary acceptor conductivity are high, it is better for a secondary acceptor to stick to the main acceptor due to an asymmetry in current pathways. Otherwise, it is better to place the secondary acceptor next to the donor to increase the amount of donor : acceptor interfaces. These results are likely most applicable to the addition of fullerene acceptors into donor : non-fullerene acceptor blends, since their potential benefits come from an increased conductance and morphology as opposed to increasing the absorption spectra.