M.M. Ivashchenko

Photoluminescence of high optical quality CdSe thin films deposited by close-spaced vacuum sublimation

Polycrystalline CdSe thin films (d1⁄40.1–3.0 μm) have been deposited on a glass substrate by means of the close-spaced vacuum sublimation technique. X-ray diffraction measurements have shown that the films obtained at Тs4473 K have only wurtzite phase. The influence of deposition conditions, in particular, the substrate temperature on the photoluminescence (PL) of CdSe films spectra was investigated. This let us study the effect of glass substrate on their optical quality as well as determine the nature and energy structure of the intrinsic defects and residual impurities in the films. The presence in PL spectrum of the most intense sharp donor bound exciton DX-line for CdSe films obtained at Ts1⁄4873 K indicates the n-type conductivity and their high optical quality. Intensive PL bands in the spectral range 1.65–1.74 eV were also observed, which are associated with the recombination of donor–acceptor pairs with the participation of the shallow donor and acceptor centers caused by Na(Li) residual impurities. As a result of the study of the PL spectra of CdSe films the optimal temperature conditions of their growth were determined, namely, the substrate temperature Ts1⁄4 873 K and the evaporator temperature Te1⁄4973 K. & 2013 Elsevier B.V. All rights reserved.

Structural properties and IR-spectroscopy of Ni- and Fe-based heterogenous metal films

In this work a structural and functional study of as-deposited and annealed iron (Fe) and nickel (Ni) heterogenous thin films deposited by electron-beam evaporation is carried out. For structural analysis are used transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). Fourier-transformed infra-red (FTIR) spectroscopy is used to analyze their compositional conditions and to measure their thickness using the novel technique (“fringing”-effect). TEM study has been shown that in both cases of obtained Fe and Ni films (as-grown and annealed) are observed the oxide phases which is confirmed by FTIR study. SAED study has been shown that in case of annealed Fe and Ni metal films are observed the halo which may be caused by the oxidation of obtained films.