To improve efficiency, third generation solar cells shall include quantum nanostructures. We developed numerical calculations within the Keldysh formalism to investigate the photovoltaic properties of a quantum wire-dot-wire concept cell. A photocurrent is produced at zero bias voltage for a very narrow range of photon energy. We moreover explain how the spectral current densities show a single peak response close to the resonance while a double peak one far from it. (c) 2013 Elsevier B.V. All rights reserved.