Mutual Diffusion of Model Acceptor/Donor Bilayers under Solvent Vapor Annealing as a Novel Route for Organic Solar Cell Fabrication

The fabrication of bulk heterojunction organic solar cells (OSCs) is primarily based on a phase demixing during solution deposition. This spontaneous process triggered when, as result decrease in the solvent concentration, interactions between donor and acceptor molecules begin to dominate. Herein, we present that interdiffusion same possible when bilayers donors acceptors are exposed vapor. Poly(3-hexyl thiophene) (P3HT), poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole) (PCDTBT) were used two types fullerene derivatives acceptors: phenyl-C61-butyric acid methyl ester (PC60BM) phenyl-C71-butyric (PC70BM), Secondary ion mass spectrometry depth profiling revealed interpenetration induced by vapor annealing was dependent component compatibility. Exposure chloroform resulted complete intermixing both components. mutual mixing increased efficiency inverted prepared model donor/acceptor bilayers. These results provide new means for incompatible components cells.