The present invention relates to photovoltaic devices which comprise: a semiconducting material able to ensure a photovoltaic effect when it is subject to electromagnetic radiation; a anti-reflective layer, transparent towards said electromagnetic radiation ensuring the photovoltaic effect, this anti-reflective layer containing, in the dispersed state, objects with dimensions of less than 5 microns, preferably less than 2 microns, said objects comprising at least two areas consisting of two different substrates, transparent towards said electromagnetic radiation and having distinct refraction indices, i.e.: a core having a first refractive index nC; and a layer surrounding the core, a so-called crust, having a second refractive index nE, distinct from the refractive index nC of the core, the ratio of the dimensions of the core to the dimensions of the core/crust assembly being comprised 1:1.5 and 1:5.