Preview

thin film

Powerful Essays
Open Document
Open Document
2583 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
thin film
Applied Surface Science 177 (2001) 152±157

Solution growth and characterization of amorphous selenium thin ®lms
Heat transformation to nanocrystalline gray selenium thin ®lms
Biljana Pejova*, Ivan Grozdanov
Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius University,
PO Box 162, Arhimedova 5, 91000 Skopje, Macedonia
Received 24 August 2000; accepted 31 January 2001

Abstract
A novel solution growth methodology for fabrication of amorphous, red selenium thin ®lms and their conversion to the hexagonal, gray modi®cation is presented. The method is based on deposition process from aqueous solution of selenosulfate by citric or ascorbic acid as oxidizing agents. The X-ray diffraction method is used for identi®cation of the deposited materials. Ultra-thin ®lms of both amorphous and hexagonal selenium are highly transparent in the Vis±NIR spectral region.
# 2001 Elsevier Science B.V. All rights reserved.
PACS: 81.15.-z; 81.05.Cy
Keywords: Selenium thin ®lm; Solution growth method; Optical band gap energy

1. Introduction
In recent years, the thin ®lms of inorganic semiconductor materials are of considerable interest in the
®eld of science and technology. Many techniques for fabrication of thin ®lms of these materials have been developed, such as solution growth, electrodeposition, physical vapor deposition, chemical vapor deposition, spray pyrolysis, etc. The solution growth technique
(also known as chemical bath deposition, electroless plating or controlled precipitation) is the simplest and most economical one. It does not require sophisticated
*
Corresponding author.
E-mail address: biljana@iunona.pmf.ukim.edu.mk (B. Pejova).

instrumentation, is convenient for both small- and large-area deposition, any kind of shape or size of the substrates can be used and the starting chemicals are commonly available and cheap materials.
Following the current trends in microelectronics
materials,



References: Chem. 9 (1999) 2889. B. Pejova, I. Grozdanov / Applied Surface Science 177 (2001) 152±157 [2] B 45 (2000) 269. [3] I. Grozdanov, M. Najdoski, S.K. Dey, Mater. Lett. 38 (1999) 28. Chem. 8 (1998) 2213. Surf. Sci. 165 (2000) 271. Films 359 (2000) 125. [13] N.N. Greevwood, A. Earnshaw, Chemistry of the Elements, 2nd Edition, Pergamon Press, Oxford, 1997 (Chapter 16). [14] P.I. Sampath, J. Chem. Phys. 45 (1966) 3519. [15] J.H. Dessauer, H.E. Clarc (Eds.), Herography and Related Processes, The Focal Press, London, 1965 (Chapter 3). [17] M. Froment, D. Lincot, Electrochem. Acta 40 (1995) 1293. [18] S. Gorer, A. Albu-Yaron, G. Hodes, Chem. Mater. 7 (1995) 1243. [19] M.T. Weller, Inorganic Materials Chemistry, Oxford Science, Oxford, 1994, p [20] R. Dalven, Introduction to Applied Solid State Physics, Plenum Press, New York, 1990, p [21] L.V. Azaroff, M.J. Buerger, The Powder Method, McGrawHill, New York, 1958. London, 1960.

You May Also Find These Documents Helpful

  • Satisfactory Essays

    The crystalline structure of ZnO thin films thus prepared was characterized via the XRD technique with a PanAlytical diffractometer. The chemical composition of the films was examined using EDS with a scanning electron microscope (SEM, Quanta 2000). The surface morphology of the films was examined in contact mode by Nanosurf easyScan 2. The optical transmittance spectra were collected at room temperature by a Safas UVmc2 UV-Vis. spectrophotometer and the photoluminescence measurements were carried out at room temperature using a He–Cd laser 325…

    • 280 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Diels-Alder Reaction Lab

    • 486 Words
    • 2 Pages

    with a regular, shiny plate-like shape. The purity of the crystals was improved as seen in the melting point for the recrystallized product.…

    • 486 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    CHEM 120L Exam Notes

    • 3033 Words
    • 13 Pages

    Ex. CuO (s) (black solid) + H2SO4 (aq) + H2O --> Cu(SO)4 (aq) (blue solution) + H2O…

    • 3033 Words
    • 13 Pages
    Powerful Essays
  • Good Essays

    This left us with the silver and chlorine which yield us silver chloride which is a solid. We did note on our observation that we had a change in color and a solid precipitate.…

    • 1019 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Geology 101: Assignment

    • 962 Words
    • 4 Pages

    What is the difference between a "crystalline" solid and an "amorphous" solid (at the atomic level)?…

    • 962 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    4.5 hw chwm

    • 458 Words
    • 2 Pages

    Lead nitrate and potassium are both transparent but when they mix t changes to a yellow color.…

    • 458 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    The purpose of this lab was to explore the properties of an unknown compound. An unknown was given and a cation flame test and anion test was performed to determine the identity of the compound. Once the identity was determined, the properties were explored.…

    • 1860 Words
    • 8 Pages
    Good Essays
  • Powerful Essays

    chem

    • 1940 Words
    • 15 Pages

    oxide formed by reacting with oxygen in the air. If there are cut, you can see the fresh shiny…

    • 1940 Words
    • 15 Pages
    Powerful Essays
  • Better Essays

    In the formation of barium white, the reaction involved was a double displacement reaction in which sodium in sodium sulfate being more reactive, was replaced by barium from barium chloride and was able to form barium sulfate, a white solid pigment and sodium chloride 2. As barium sulfate is insoluble in water it was relatively easy to observe and interpret what was happening as the chemicals mixed 2. The formation of zinc yellow also involved a double displacement reaction 3. The addition of zinc sulfate to potassium chromate formed a yellow coloured solution and when base was added, the solution turned into a bright yellow colour. This was difficult to observe as the colour change was very subtle, however, interpretation was manageable as pH paper was used to find when the addition of base should be stopped. Chromium oxide green was synthesized from the reaction between potassium dichromate and sulfur. The reaction involved heat thus, sulfur dioxide gas was released and colour change was observed from bright red to black. The final inorganic pigment was dark green. Due to the colour change it was easy to observe and interpret what was happening as the reactions progressed. The formation of Prussian blue used a microscopic reaction, that is the reactants were mixed together and their chemical reaction observed under a microscope. Prussian blue was produced by the oxidation of potassium ferrocyanide by ferric chloride and its product was observed to be insoluble in water 4. This was hard to observe as the reaction proceeded very quickly, as soon as the reactants touched each other the blue of the Prussian blue was observed, however the completion of the reaction was easy to observe due to the drastic colour difference. The macroscopic reactions…

    • 1368 Words
    • 6 Pages
    Better Essays
  • Powerful Essays

    Natural Water Lab

    • 3329 Words
    • 14 Pages

    cation resin exchange. For the first method, the desired effect can be achieved through simply…

    • 3329 Words
    • 14 Pages
    Powerful Essays
  • Good Essays

    Properties of Hydrates

    • 1038 Words
    • 5 Pages

    2. Heat gently with a burner flame and observe carefully. If droplets of water appear on the test tube it may be a hydrate. Note the nature and color of the residue.…

    • 1038 Words
    • 5 Pages
    Good Essays
  • Powerful Essays

    University of Chemical Technology and Metallurgy 8 Kl. Ohridski, 1756 Sofia, Bulgaria E-mail: e-mail: manahova@abv.bg.…

    • 2141 Words
    • 9 Pages
    Powerful Essays
  • Good Essays

    The grown Cd doped LSMH crystal were subjected to powder X-ray diffraction studies using a Rich Seifert X-ray diffractometer employing CuKα (1.54058 Å) radiation, scanning angle ranging from 10° to 70° at a scan rate 1°/min to confirm the crystalline phase of the grown crystal. Fig 2 shows the X-ray powder diffraction patterns of pure as well as Cd doped LSMH single crystals. The obtained (h k l) values are indexed using the JCPDS software. It belongs to the monoclinic structure of space group is P21 and the lattice parameters are a=5.449 Å, b=4.832Å and c=8.137 Å & β =107.19˚ [JCPDS No. 840649]. The observed prominent peaks of Cd doped LSMH are (001), ( 01), (011), (101), (110),…

    • 1017 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Soluble glass, also called foam alkali, is an alkali metal air hardening material. In construction, it is usually used to prepare sodium silicate cement, soluble glass mortar, and soluble glass concrete. Soluble glass is widely used in the anti-acid and heat-resistant engineering. The main method to produce soluble glass is to grind and stir calcined soda and quartz sand which are the major raw materials, then fuse them in the melting pot of 130O-140OnC, and finally cool them into solid soluble glass. Considering the differences of alkali metal oxide, soluble glass can be divided into sodium silicate and potassium silicate, and sodium silicate is often used. Among the components of sodium silicate (Na2O*nSiO2), the ratio of silicon oxide molecules to sodium oxide molecules is known as the module of soluble glass, generally between 1.5 to 3.5. And the number of module decides the properties and performance of soluble glass. The solid soluble glass with low module is relatively easy to dissolve in water. The bigger the number is, the higher the viscosity is and the harder it dissolves in water; the soluble glass with low module, there are many kinds of crystal composition and the cohesive force is poor, and when the module number improves, the colloid component increases and the cohesive force rises.…

    • 521 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    Reflectivity

    • 3147 Words
    • 13 Pages

    Introduction---------------------------------------------------------------[1] 2) Film deposition-----------------------------------------------------------[2] 3) Basic principle of x-ray reflectivity-------------------------------------[3] 4) Reflection and refraction at the boundary----------------------------[5] 5) X-ray reflectivity…

    • 3147 Words
    • 13 Pages
    Powerful Essays

Related Topics