Influence of swift heavy ion irradiation on the photoluminescence of Si-nanoparticles and defects in SiO 2

• Published in: Nanotechnology 2017-09, Vol.28 (37), p.375603
• Main Authors: Chulapakorn, Thawatchart, Sychugov, Ilya, Saveda Suvanam, Sethu, Linnros, Jan, Primetzhofer, Daniel, Hallén, Anders
• Format: Article
• Language: English
• Subjects: ion implantation; photoluminescence; silicon nanoparticle; swift heavy ion irradiation
• ISSN: 0957-4484; 1361-6528; 1361-6528
• DOI: 10.1088/1361-6528/aa824f

The influence of swift heavy ion (SHI) irradiation on the photoluminescence (PL) of silicon nanoparticles (SiNPs) and defects in SiO -film is investigated. SiNPs were formed by implantation of 70 keV Si and subsequent thermal annealing to produce optically active SiNPs and to remove implantation-induced defects. Seven different ion species with energy between 3-36 MeV and fluence from 10 -10 cm were employed for irradiation of the implanted samples prior to the thermal annealing. Induced changes in defect and SiNP PL were characterized and correlated with the specific energy loss of the employed SHIs. We find that SHI irradiation, performed before the thermal annealing process, affects both defect and SiNP PL. The change of defect and SiNP PL due to SHI irradiation is found to show a threshold-like behaviour with respect to the electronic stopping power, where a decrease in defect PL and an anticorrelated increase in SiNP PL after the subsequent thermal annealing are observed for electronic stopping exceeding 3-5 keV nm . PL intensities are also compared as a function of total energy deposition and nuclear energy loss. The observed effects can be explained by ion track formation as well as a different type of annealing mechanisms active for SHI irradiation compared to the thermal annealing.