Affiliation: | a Department of Physics, Yeungnam University, Daedong, Gyeongsan 712-749, South Korea b School of Nano Engineering, Inje University, Gimhae 621-749, South Korea c Nanomaterials Laboratory, National Institute for Materials Science, Ibaraki 305-0047, Japan d Department of Physics, Kyunghee University, Suwon 449-701, South Korea e Department of Visual Optics, Kyungwoon University, Gumi 730-850, South Korea f Wafering R&D Center, LG Siltron, Gumi 730-724, South Korea |
Abstract: | Strong red photoluminescence (PL) spectra appeared at porous silicon (PS) samples prepared by a chemical anodization of Fe-contaminated Si substrates. The Fe1000 sample with Fe contamination of 1000 ppb showed a ten times stronger red PL than that of the reference PS sample without any Fe contamination, and this sample also showed the higher thermal stability for PL spectra as compared with the reference PS sample. Furthermore, the PL intensity from the PS with Fe contamination is linearly proportional to the Fe-related trap concentrations of Si substrates obtained from DLTS. Especially, all the PS samples exhibit the same PL peak position regardless of Fe contamination concentrations, as compared with that of the reference PS. This means that there is no significant effect such as the variation of size distribution of nanocrystalline Si in PS layer formed on Fe-contaminated Si substrate. Based on the results of PL and DLTS, we found that the PL efficiency depends strongly on the Fe-related trap concentration in Si substrates. |