Donor-acceptor dyads are very promising compounds for low-cost organic photovoltaic devices. The orientation of porphyrin-fullerene dyads TBD6a and DHD6ee formed on a solid substrate by the Langmuir-Schaefer method is considered. It was shown by X-ray reflectivity that molecular orientation persisted during that transmission from liquid to solid surface in spite of the dyad molecules low anisometry. 2016 Mendeleev Communications. Published by ELSEVIER B.V.