Use of porous GaAs electrodes in photoelectrochemical cells

The photoelectrochemical properties of semiconductor‐electrolyte solar cells with carbon auxiliary electrode and colloidal aqueous solution of Na2SiO3 have been investigated. Bulk n‐type single crystalline and nanoporous GaAs material were used as semiconductor electrodes. Current–voltage characteristics under different illumination intensities and spectral distribution of the photosensitivity were studied. The photopotential was found to reach values as high as 0.46 V for bulk n‐GaAs. The introduction of porosity in GaAs shifts the maximum of the spectral distribution of photosensitivity towards the longwavelength region and increases the short circuit current by a factor of two. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)