Natural photosynthetic structures utilize chlorophylls to absorb light and carry out photochemical charge separation to store light energy. Porphyrins and related derivatives, as analogues of chlorophylls, have been investigated as active materials for dye-sensitized solar cells and a record PCE of 13% has been achieved. Although porphyrins have been less studied for solution-processed BHJ OSC, impressive progress has been made in this field along the last years achieving remarkable efficiencies as high as 9.06% [1].

In this presentation, I will present our recent work tailoring porphyrin-based A-D-A [2][3] and D-A-D [4] small molecules used as donor materials in BHJ solar cells, reaching excellent efficiencies, higher than 9% with energy loss lower than 0.6 eV [5]. The influence of modification of the substitution in meso positions, role of the conjugated bridge and nature of the acceptor groups on the frontier orbital levels and band-gap as well as the photophysical and electrochemical properties will be discussed.

1. Gao, J. Miao, L. Xiao, W. Deng, Y. Kan, T. Liang, C. Wang, F. Huang, J. Peng, Y. Cao, F. Liu, T. P. Russell, H. Wu, X. Peng. Adv. Mater. 28, 4727 (2016).
2. Morán, S. Arrechea, P. de la Cruz, V. Cuesta, S. Biswas, E. Palomares, G.D. Sharma, F. Langa. J. Mater. Chem. A, 4, 11009 (2016).
3. Arrechea, A. Aljarilla, P. de la Cruz, E. Palomares, G. D. Sharma, F. Langa. Nanoscale 8, 17953 (2016).
4. Arrechea, A. Aljarilla, P.de la Cruz, M. K. Singh, G. D. Sharma, F. Langa. J. Mater. Chem. C. 5, 14259 (2017).
5. Vartanian, S. Arrechea, R. Singhal, P. de la Cruz, F. Langa, G. D. Sharma. Submitted.