Optical and photospectral properties of CrSi2 A-type epitaxial films on Si(111)
1997; Elsevier BV; Volume: 311; Issue: 1-2 Linguagem: Inglês
10.1016/s0040-6090(97)00678-0
ISSN1879-2731
AutoresN. G. Galkin, A. M. Maslov, A. V. Konchenko,
Tópico(s)Surface and Thin Film Phenomena
ResumoOptical functions (α(ω), n(ω), k(ω), ε1(ω), ε2(ω), Im ε−1(ω), G(ω), σopt(ω), 1/(n2−1)) of the CrSi2 A-type epitaxial films 100 nm thick, grown by template method, have been studied by transmittance and reflectance spectroscopy in the energy range of 0.09–1.1 eV. A detailed analysis of the absorption coefficient data (α(ω)) indicates that epitaxial CrSi2 A-type film is a semiconductor with a direct forbidden energy gap of about Eg=0.37 eV. Undispersed refraction index region (with n0=4.38) lies at energies below Eg=0.37 eV. This confirms the existence of fundamental absorption edge. Additionally, two direct interband transitions Eg1=0.73 eV and Eg2=0.93 eV with the greater state densities have been observed in the energy range 0.6–1.1 eV. Three direct interband transitions in the used energy range are responsible for the formation on the whole of all optical functions. The intrinsic photoeffect in the CrSi2 A-type epitaxial films has been studied by photoconductivity method. The spectral dependence of photoconductivity in the energy range of 1.0–1.6 eV and the integral photoconductivity signal (in the energy range of 0.5–0.83 eV) of the CrSi2 A-type epitaxial films were registered in the first time.
Referência(s)