Effect of Polymer Fraction on Refractive Index of Nanocrystalline Porous Silicon

Porous Silicon on Insulator Technology

“…The porosity of the porous silicon samples depends upon the fabrication parameters. The porosity can determine easily by weighing measurements or the geometric method using SEM analysis and is given by [10]:…”

“…The porous silicon is a composite material with a combination of single crystal silicon (c-Si) and voids and the refractive index of a porous silicon layer is expected to be lower than that of bulk silicon. The Bruggeman (equation 4) [10,11] is used to determine the refractive index (n) of porous silicon as follows:…”

“…Where A ** is the effective Richardson's constant, which equals 32(A/K 2 .cm 2 ) for P-type silicon and Ф Bn (e V) is the barrier height while Fig. (5,b) shows the barrier height, it calculated from equation (10), the increasing in barrier height with increasing oxidation temperature was observed and it varied from (0-561to 0,698 eV). The increasing in barrier height with increasing oxidation temperature attributed to depending on the barrier height for PS on the barrier height of the M/PS/n-Si/M ,the PS/c-Si interface have pinning which acts as a defect in the interface and caused increase in saturation current [15], after oxidation the interface layer becomes clean by replacing unstable hydrogen and oxygen by pure and stable oxide atoms that decrease saturation current subsequently increasing barrier height [12][13][14][15][16][17][18][19][20].…”

“…Various oxidation approaches, such as chemical oxidation, anodic oxidation [5], conventional furnace oxidation [6], thermal oxidation [7,8] and aging oxidation [9], are used to generate a more stable O-passivated surface to replace the unstable H-passivated surface. Furthermore, those oxidation ways can improve efficiency of light emission [10,11]. The scientists and researchers observed that, the film, which growth by anodic oxidation method stay several chemical ions after the deposition that has an effect on electrical properties, which cause instability of the device after oxidation with having different stress.…”