Isothermal Close Space Sublimation (ICSS) technique was used for embedding porous silicon (PS) films with ZnTe. It was studied the influence of the preparation conditions and in particular of a chemical etching step before the ZnTe growth, on the composition profile and final porosity of ZnTe embedded PS. The structure of the embedded material was determined by x-ray diffraction analysis while the thickness of the samples was determined by scanning electron microscopy (SEM). Rutherford backscattering (RBS) and Energy Dispersive (EDS) spectrometries allowed determining the composition profiles. We conclude that the etching of the PS surface before the ZnTe growth has two main effects: the increase of the porosity and enhancing the reactivity of the inner surface. It was observed that both effects benefit the filling process of the pores. Since RBS and EDS cannot detect the porosity in the present system, we explore the evolution of porosity by the fitting of the UV-VIS reflectance spectra. The atomic percent determined with this method was in relatively good agreement with that obtained from the RBS and EDS measurements. * Telephone: 00 537 8788950 ext 209/ fax: 00 537 8783471, omelo@fisica.uh.cu Manuscript revised Click here to download Manuscript: demelo et al revised.doc Click here to view linked References PACS: 81.05.Dz, 47.56.+r, 78.20.-e Porous silicon is a promising matrix host for embedding different materials, such as semiconductors, metals or conductive oxides [1,2] with a wide range of applications. This is because the properties of both the PS and the embedded material can result modified in the final composite. Several techniques have traditionally been used to infiltrate PS films. They include sol-gel [3], multiple step process including impregnation and thermal or chemical treatments [4], atomic layer deposition [5], and electro-deposition [6] among others. In a previous paper we reported the use of Isothermal Close Space Sublimation (ICSS) technique for embedding PS films with CdSe and ZnTe semiconductors [7]. It was demonstrated that for these semiconductors, approximately constant composition profiles can be obtained inside the pores. In the present paper, we study the influence of the preparation conditions on the compositional profile, morphology, and final porosity of ZnTe embedded PS. X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), scanning electron microscope (SEM) and energy dispersive x-rays (EDS) and UV-VIS reflectance spectroscopies were used to characterize the samples. 2. Experimental details Porous silicon (PS) layers were prepared by electrochemical etching of monocrystalline p + (100) silicon wafers in a 1:1 ethanol and HF (48% wt.) electrolyte. The process took place in a Teflon cell under illumination provided by a 150 W halogen lamp to increase final porosity. Anodization current was provided by a computer-controlled HG&G 263 galvanostat/ potentiostat. Applied current density was 150 mA/cm 2 . This set-up is known to produce homogeneous, sponge-like mesopo...
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