A stand-alone device comprising a silicon wafer having its front surface including a first layer of a first conductivity type and a second layer of a second conductivity type forming a photovoltaic cell; first vias crossing the wafer from the rear surface of the first layer and second vias crossing the wafer from the rear surface of the second layer; metallization levels on the rear surface of the wafer, the external level of these metallization levels defining contact pads; an antenna formed in one of the metallization levels; and one or several chips assembled on said pads; the metallization levels being shaped to provide selected interconnects between the different elements of the device.