Varied morphology of porous GaP(111) formed by anodization

In this paper, porous Gal? was prepared by electrochemical etching under dark conditions at room temperature. Via different electrolyte systems, various pore morphologies were obtained. To match up appropriate operating potential, the intact pores could be obtained. The pore morphology was modified by immersing the wafer in a nitric or nitrate solution for chemical etching after anodization, which exhibited regular pores with a uniform pore size. It appears this step not only dissolves the upper nucleation oxide layer, but also changes the pore morphology. Using nitric acid instead of sulfuric acid as the electrolyte for anodization. Uniform high density three-dimensional nano scale pores can be obtained. The result may be applied to fabricating photonic crystal material. (C) 2007 Elsevier B.V. All rights reserved.