Structural and optical analysis ofβ−FeSi2thin layers prepared by ion-beam synthesis and solid-state reaction

Abstract

The ␤-FeSi 2 phase was fabricated using two different techniques: ion-beam synthesis and solid-state reaction of a thin Fe layer with Si substrate. The crystal structure of the films was investigated by grazing incident asymmetric x-ray diffraction. The generalized matrix method was used to obtain the dispersions of the absorption coefficient ␣(E) and of the refractive index n(E) from the experimental transmittance and reflectance spectra, accounting for the surface and interface roughness. From ␣(E) and n(E) dependences a direct band-gap energy, E g ϭ0.80 eV was determined. When interpreting quantitatively the ␣(E) dependences, the Burstein-Moss effect was considered.

Structural and optical characterization of the formation of β-FeSi2nanocrystallites in an n-type (100) Si matrix

“…(b) The interband transitions in the β-FeSi 2 sheets and needles with different sizes also contribute to the optical constants behaviour. In our previous investigations of comparatively thick (∼100 nm) continuous ion-beam synthesized β-FeSi 2 layers [12], we showed that the absolute maximum in the dispersions of the refractive index lies at about 0.80 ± 0.02 eV, determining the value of the β-FeSi 2 direct band gap at the -point most likely. The behaviour of the refractive index dependences, shown in figure 6, is quite different for the following reasons: (i) the β-FeSi 2 phase amount is lower, meaning much more transparency, which also allows higher energy transitions to be detected.…”

Structural and Optical Dispersion Characterisation of Sprayed Nickel Oxide Thin Films

“…where ω p is the plasma frequency and 2 2 p o e N m    * , and ω the incident light frequency [30,31]. From the approximation of the linear part of the dependences n 2 (λ 2 ) of NiO films deposited at different substrate temperatures, and ε (2) are shown in insert graph and tabulated in Table 1.…”

Optical and Photoelectric Properties of TlInS2 Layered Single Crystals

“…From the approximation of the linear part of the dependences n 2 (λ 2 ) of the TlGaSe 2 layered single crystal to λ=0 and n =0 the values of (ε ∞ ) and (ω P ) were found [13,14].…”