Multiple semiconductors thin film solar cells

Nano technologies may dramatically improve the efficiency of thin film silicon solar cells. The paper presents computational results for a third generation solar cells based on III/V group semiconductor nanoparticles embedded in the silicon substrate. The combination of light trapping and multi-band gap active device can allow achieving higher quantum efficiency in solar cells. The use of embedded noble metal nanoparticles can produce considerable improvements versus the bare thin film silicon solar cell as well as versus the thin film silicon solar cell with the noble metal nanoparticles deposited on top of the silicon substrate despite the large parasitic losses of the metal. An extension of this principle by using submerged nanoparticles made by direct band-gap semiconductors such as InAs or GaAs may permit better results not having parasitic losses and with the extra advantage of extending the spectral region of light absorption compared to pure thin film silicon, as for a multi-band gap solar cell.