Ismail Khalaf Abbas¹, Laith Ahmed Najam^1,, Abd UlKahliq AuobSulaiman¹

Porous silicon layers (PSi) were prepared from p-type silicon wafer by using electrochemical cell with etching time 20 min, current 30 mA and fixed electrolyte solution HF:C₂H₅OH (1:4). The effect of increase of γ-ray intensity (50Gy and 100Gy) on the structural properties of porous silicon has been studied using SEM, AFM, XRD and Raman spectrum. The SEM images before irradiation shows high density and randomly distributed of pores that cover all of the surface which have different size and spherical shape. After irradiation by 50Gy, the pores seems more obvious, discriminate and larger diameters. The initial elementary pores on the PSi surface decrease with the increasing of radiation intensity to 100Gy, as a result of formation of new pores with in the initial layer of Psi. The AFM images show that the roughness of the samples increase with irradiation. XRD spectrum before irradiation did not show clearly any featured peaks while the spectra after irradiation show the presence of different peaks but the most important distinctive was <111> peaks at ( 2θ = 28.12) which give indication that the structure is cubic. An extremely symmetric band shape were recognized from Raman spectra of the samples after and before irradiation.

porous silicon, gama radiation, photoluminescence, SEM of PSi, XRD of PSi, AFM of PSi