Organic solar cells bulk heterojunction structure

Another method that was successfully applied for the formation of a nano-structured bulk heterojunction organic solar cell is nanoimprint lithography (NIL). In direct comparison with a flat bilayer organic solar cell design, the nanostructured version exhibited nearly a double increase in solar PCE [119]. 

Small molecule semiconductors for bulk heterojunction organic solar cells are attractive because of their advantages over their polymer counterparts, which include well-defined molecular structure, definite molecular weight, and high purity without batch-to-batch variations. 

Figure 18.1 Structural configurations of typical solar cell made on glass substrate with transparent indium tin oxide (ITO) electrode. The active layer can typically have three configurations (1) single organic layer, (2) bilayer (double-layer) heterojunction between donor and acceptor and (3) bulk heterojunction...

Figure 47 Schematic layout of organic fullerene/polymer solar cell, (a) Phase segregation on the nanoscale creates bulk heterojunction in the active layer, which allows for efficient photon harvesting and charge generation and (b) molecular structures of classical fullerene-based and pol3mer-based materials most widely investigated in organic bulk heterojunction solar cells. (Reproduced from Ref. 156. American Chemical Society, 2004.)...

Figure 76 (a) Molecular structure of F-PCBM and (b) a schematic layout of organic bulk heterojunction solar cell with self-assembled... 

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