| 1. |
- Bukaluk, A., et al.
(författare)
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Auger electron spectroscopy, ellipsometry and photoluminescence investigations of Zn1-XBeXSe alloys
- 2001
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Ingår i: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 175-176, s. 531-537
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, properties of the Zn1-XBeXSe crystals grown from the melt by the high-pressure Bridgman method are reported. Spectroscopic ellipsometry has been used for determination of the complex dielectric function of Zn1-XBeXSe. On the basis of the photon energy dependence of the dielectric function, the energy gaps of alloys containing different beryllium concentrations have been evaluated. Measurements of the photoluminescence (PL) spectra allowed to find the excitonic gap in the investigated alloys. Auger electron spectroscopy (AES) with simultaneous argon ion sputtering has been used for determination of surface composition. AES investigations allowed to make predictions concerning distribution of particular elements in the samples. © 2001 Elsevier Science B.V.
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| 2. |
- Wronkowska, A.A., et al.
(författare)
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Characterisation of Cd1-xMgxSe solid solutions by spectroscopic ellipsometry
- 2001
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Ingår i: Vacuum. - 0042-207X .- 1879-2715. ; 63:1-2, s. 233-239
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Optical properties of bulk Cd1-xMgxSe mixed crystals, grown from a CdSe, Mg, and Se melt by the Bridgman method, are presented. The alloys have a wurtzite type structure in the investigated range of composition, i.e. for 0 = x = 0.4. Measurements of the complex pseudo-dielectric function, = + ie2(?)>, were performed at room temperature in the photon energy range of 1.25-4.5 eV, using a computer-controlled variable angle of incidence ellipsometer. The spectral dependence of the effective refractive index and the absorption coefficient were also derived. The structure observed in the dielectric functions, attributed to the interband transitions E0, E0 + ?0 and E1, have been analysed by fitting the and d2/d?2 spectra to the damped harmonic oscillator and critical-point line shapes, respectively. For all critical points, the energy increases with increasing Mg concentration. The ellipsometric results of a fundamental band-gap shift due to Mg content are compared with the rate of increase of the excitonic energy, derived from photoluminescence spectra. © 2001 Elsevier Science Ltd.
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| 3. |
- Wronkowska, A.A., et al.
(författare)
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Investigations of Cd1-xMnxTe crystals by means of ellipsometry and Auger electron spectroscopy
- 2003
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Ingår i: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 212-213:SPEC., s. 110-115
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Cd1-xMnxTe crystals, obtained by the high-pressure Bridgman method for x = 0, 0.27, 0.49, 0.67 and 0.8, were investigated. Crystal composition was determined by electron microprobe analysis. For an Mn content lower than 0.7, a single phase of pure zinc blend structure was found. In Cd0.2Mn0.8Te samples a two-phase structure was revealed. Auger electron spectroscopy (AES) was used to determine the composition of the crystal surfaces. AES depth profiles obtained by argon sputtering and AES analysis allowed to find the distribution of Cd, Mn and Te inside the sub-surface region. Spectroscopic ellipsometry was applied to determine the complex dielectric function e of the samples. Ellipsometric measurements were performed at room temperature in the photon energy range 0.75-6.5 eV. The spectral dependence of e was used to find the energy gaps Eg of the alloys with different Mn content. Ellipsometric data were correlated with the compositional results obtained from the electron microprobe and AES depth profile investigations. A linear increase of energy gaps with increasing x was observed for chemically homogeneous CdMnTe crystals. © 2003 Elsevier Science B.V. All rights reserved.
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| 4. |
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| 5. |
- Wronkowska, A.A., et al.
(författare)
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Spectroscopic ellipsometry and photoluminescence investigation of Zn1-x-yBexMgySe and Cd1-x-yBexZnySe Crystals
- 2008
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Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley-VCH Verlagsgesellschaft. - 1862-6300 .- 1862-6319. ; 205:4, s. 854-858
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Tidskriftsartikel (refereegranskat)abstract
- Optical and luminescence properties of the Bridgman-grown Cd1–x –yBex Zny Se and Zn1–x –yBex Mgy Se crystals are reported. Spectroscopic ellipsometry was employed for determination of spectral dependence of the complex dielectric function (E) in the photon energy range 0.75–6.5 eV. Below the absorption edge the refractive indices n (E) of the alloys were modelled using a Sellmeier-type relation. The excitonic band-gap energies were estimated from the ellipsometric and photoluminescence measurements. Compositional effects in the ellipsometric and photoluminescence spectra are discussed.
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