Three-dimensional Self-organization of Tetraphenylporphyrin and its Composites with C60: Structure and Optical Properties

Abstract

Background: Thin films of a 5,10,15,20-tetraphenylporphyrin (H2TPP) and its metal complexes (MeTPP, where Me = Co, Cu, Zn, Fe-Cl) were obtained by vacuum thermal evaporation under quasi-equilibrium conditions (hot wall method) and by coating from a toluene solution on various substrates. It was shown that H2TPP, CuTPP and CoTPP have an ability to selforganization into linear structures during crystallization (nanowhiskers, nanowires, or nanorods), regardless of our obtaining method. Methods: FeClTPP and ZnTPP crystallize into planar films with the same preparation technique. Co-deposition with fullerene C60 allows obtaining fullerene crystallites on the surface of tetraphenylporphyrin, subsequently creating the so-called bulk heterojunctions. Results: The possibility of controlling the shape of obtained crystallites by changing technological parameters and substrates has been shown for metal free tetraphenylporphyrin. High degree crystalline ZnTPP and H2TPP films are characterized by a red shift of photoluminescence and absorption spectra under crystallization. Conclusion: A change in the relative intensity of the photoluminescence spectrum maxima of various nature is observed during transition from amorphous to crystalline structure of H2TPP.