Efficient small-molecule photovoltaic cells using nanostructured template

We report a simple method to achieve efficient nanostructured organic photovoltaics via patterning copper iodide (CuI) nano-rod template on indium tin oxide. The CuI nano-rod sheet was fabricated by glancing angle deposition method. The strong interfacial interaction between zinc phthalocyanine (ZnPc) and CuI leads to the formation of nano-pillar arrays with lying-down crystalline order, which greatly improve absorption efficiency and surface roughness for exciton dissociation. Optimized ZnPc/C60 bilayer cell has a power conversion efficiency of 4.0 ± 0.1%, which is about three-fold larger than that of conventional planar cell. In addition, we also reported the new type of nano-structured template based on organic semiconductor. As the template material, diindenoperylene (DIP) was introduced into bilayer photovoltaic cells using based on tetraphenyldibenzoperifl anthene (DBP) and C60. While the basic molecular structure of DIP is similar to that of DBP, DIP shows higher crystallinity than DBP one. We obtained power conversion efficiency of 5.2% and high fill factor of 0.72 due to high crystallinity of DIP nano-structured template.