We wish to perform PNR measurements on organic spin valve devices to assess the effect on the device performances of the spin relaxation mechanisms related to spin-orbit interaction in the organic layer.For this reason we will grow devices in which the organic layer is tris(8-hydroxyquinolate)aluminium (Alq3), and the isostructuaral molecules Gaq3 and Inq3, where the Al atom is substituted with Ga and In, respectively, which have a considerably higher spin-orbit coupling. Understanding the effects of increased spin relaxation due to increased spin-orbit coupling in the organic layer of organic spin valves could have a significant impact on the improvement of the performances of such devices.