Cathodoluminescence of crystalline and amorphous SiO2 and GeO2

Visualization of microscopic stress fields in silica glass in the scanning electron microscope

“…1. A yellow (Y) band arises from the presence of structural water, 10) while the ultraviolet band at about 290 † Corresponding author: G. Pezzotti; E-mail: pezzotti@chem.kit. ac.jp nm (UV band, henceforth) originates from trivalent silicon centers and/or from other point-defects generated by electron beam irradiation.…”

“…10) Precise characterizations of the spectral shift rate with applied stress have been shown elsewhere, 7) according to different calibration methods. The shift rate, which is usually referred to as the PS coefficient, is a material property.…”

“…The Grabner's tensorial equation for the stress state nearby the interface can be re-written, as follows: (13) where, T and T -1 are transformation matrices, Ψ is the rotation angle for the Cartesian system, and the parameter, Λ, is computed as follows: (14) where, σxy, σzz, and τxz are given by Eqs. (9), (10), and (11), respectively.…”

Cathodo- and Photo- Luminescence of Silicon Rich Oxide Films Obtained by LPCVD

“…Luminescent emission at 460 nm (2.7 eV), 520 nm (2.4 eV) and 650 nm (1.9 eV) are mainly related to defects such as Oxygen deficiency-related centers (ODC) or oxygen vacancies (Cervera et al, 2006;Fitting, 2009;Gritsenko et al, 1999), E'δ defect or peroxide radical (Goldberg et al, 1997) and non-bridging oxygen hole centers (NBOHC) (Fitting, 2009;Fitting et al, 2001;Gritsenko et al, 1999), respectively. Since CL measurements have shown luminescent peaks (or distributions) close to those wavelengths, such defects could be inside the SRO films.…”

“…In summary, luminescence peaks at 460, 520, and 620 nm are mainly due to defects such as Oxygen deficiency-related centers (ODC), E'δ defect, and non-bridging oxygen hole centers (NBOHC), respectively (Cervera et al, 2006;Fitting et al, 2001;Inokuma et al, 1998). Electroluminescence (EL) studies on SRO films with the same silicon excess as in this work exhibit an emission band similar to our CL results with peaks at 450, 500, 550, and 640 nm (Morales-Sánchez et al, 2010).Then the mentioned defects should exist into the SRO films, which are only excited with electron of high energy generated by CL or by EL.…”