The electrical transport properties of films derived from aqueous semiconducting nanoparticle are fully described by a phenomenological model that relates intrinsic film morphology to photovoltaic response. The model is applied to a new bulk heterojunction blend, composed of organic semiconducting nanoparticles formed from the polymer donor poly[{2,6-(4,8-didodecylbenzo[1,2-b:4,5-b']dithiophene)}-alt-{5,5-(2,5-bis(2-butyloctyl)-3,6-dithiophen-2-yl-2,5dihydropyrrolo[3,4-c]57pyrrole-1,4-dione)}] (P(TBT-DPP)) and the fullerene indene-C-60-bisadduct (ICBA) synthesized by the miniemulsion method. The nanoparticle inks are printed from an aqueous dispersion onto flexible ITO-free substrates yielding power conversion efficiency of 2.6%. (C) 2015 Elsevier B.V. All rights reserved.