The correlation between the chemical and physical modifications induced by 3 MeV An ions, in the fluence range I x 10(13)-1 x 10(15) ions/cm(2), and the optical properties of thin films of polyhydroxymethylsiloxane are reported and discussed. In particular, the XPS results confirmed that irradiation at high energy leads to a ceramic-like SiOxCyHz phase, still keeping most of the initial carbon content. while the Raman spectra show the appearance, at a fluence of 2 x 10(14) ions/cm(2) of the characteristic band shape due to the formation of a-C:H clusters with a semiconducting behaviour. A careful analysis of the intense luminescence peak in the Raman spectra show evidence of the occurrence of a red shift in the emission spectra, indicating a reduction of the band gap of the emitting C-clusters of about 0.25 eV. in agreement with the results of reflectance UV-Vis spectra. consistent with a decrease 35% of the optical thickness with increasing ion fluence. (C) 2002 Elsevier Science B.V. All rights reserved.
High-energy ion-beam-induced modification of the optical properties of polysiloxane films
MARLETTA, Giovanni
2002-01-01
Abstract
The correlation between the chemical and physical modifications induced by 3 MeV An ions, in the fluence range I x 10(13)-1 x 10(15) ions/cm(2), and the optical properties of thin films of polyhydroxymethylsiloxane are reported and discussed. In particular, the XPS results confirmed that irradiation at high energy leads to a ceramic-like SiOxCyHz phase, still keeping most of the initial carbon content. while the Raman spectra show the appearance, at a fluence of 2 x 10(14) ions/cm(2) of the characteristic band shape due to the formation of a-C:H clusters with a semiconducting behaviour. A careful analysis of the intense luminescence peak in the Raman spectra show evidence of the occurrence of a red shift in the emission spectra, indicating a reduction of the band gap of the emitting C-clusters of about 0.25 eV. in agreement with the results of reflectance UV-Vis spectra. consistent with a decrease 35% of the optical thickness with increasing ion fluence. (C) 2002 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
