• Morphological and optical properties of n-type porous silicon: effect of etching current density

    • Fulltext


        Click here to view fulltext PDF

      Permanent link:

    • Keywords


      Porous silicon; anodization; reflectance; photoluminescence; Raman spectra.

    • Abstract


      Morphological and optical properties of porous silicon (PS) layer fabricated on n-type silicon wafer have been reported in the present article. Method of PS fabrication is by photo-assisted electrochemical etching with different etching current densities ($J$). Porosity and PS layer thickness, obtained by the gravimetric method, increase with increasing $J$. Pore morphology observed by FESEM shows the presence of randomly distributed pores with mostly spherical shape. Calculated pore size is also seen to increase with increasing value of $J$. XRD gives the characteristic amorphous peak of PS along with some peaks corresponding to crystalline silicon (c-Si). Calculated crystallite size shows decreasing trend with increasing $J$ value. The optical properties of these samples have been investigated by UV–visible reflectance, Raman spectroscopy and photoluminescence (PL) spectra. Reflectance measurement shows blue-shift of the spectrum with increased reflectivity for increasing $J$. Raman spectra show remarkable blue-shift with respect to the c-Si peak. PL spectra give the luminescence energy in the orange–red region of the visible spectrum and little change with variation of $J$.

    • Author Affiliations


      M DAS1 D SARKAR1

      1. Department of Physics, Gauhati University, Guwahati 781014, India
    • Dates


© 2017 Indian Academy of Sciences, Bengaluru.