some "small" molecules applications in photovoltaics

?-conjugated organic molecules have found a relevant field of application in photovoltaics either as light harvesters and/or charge transporting materials in, among the others, dye-sensitized solar cells (DSSC), perovskite solar cells (PSC) and organic photovoltaic (OPV) cells. In first part of my talk, I will report the results of the synthesis and characterization of novel porphyrins and phthalocyanines for DSSC1. Such dye families have been extensively studied in the last years reaching efficiency values up to, respectively, 12% 2 and 6.4% 3. Phthalocyanines are less efficient than porphyrins but have a greater chemical stability that could favor their potential application in building-integrated-photovoltaics as the lack of stable blue and green dyes with an acceptable stability once exposed to thermal stress and UV irradiation remains an unsolved problem. An ongoing activity on the use of symmetrical phthalocyanines and their analogues as hole transporting materials for PSCs will also be briefly shown. In the second part of the talk I will demonstrate long term outdoor stability of OPV cells based on tetraphenyldibenzoperiflanthene (DBP):C70 planar-mixed heterojunction with 2,2',2"-(1,3,5-benzenitryl tris-[1-phenyl-1H-benzimidazole] (TPBi):C70 electron-filtering cathode buffer layers.4 REFERENCES 1)Walter, M. G.; Rudine, A. B.; Wamser, C. C., J. Porphyrins Phthalocyanines, 2010, 14 (09), 759-792. 2)Yella, A.; Lee, H. W.; Tsao, H. N.; Yi, C.; Chandiran, A. K.; Nazeeruddin, M. K.; Diau, E. W.; Yeh, C. Y.; Zakeeruddin, S. M.; Gratzel, M. Science, 2011, 334, 629-634. 3) Ikeuchi, T.; Nomoto, H.; Masaki, N.; Griffith, M. J.; Mori, S.; Kimura, M. Chem Commun., 2014, 50, 1941-1943. 4)Q. Burlingame, Q.; Song, B.; Ciammaruchi, L.; Zanotti, G.; Hankett, J.; Chen, Z.; Katz, E. A. and Forrest, S. R. Adv. Energy Mater., 2016. DOI: 10.1002/aenm.201601094