Zinc halides have been used of the growth of ZnS:M2+ (M = Mn, Co, Cu) single-crystal one-dimensional nanostructures by halide-transport CVD (HTCVD) process at relatively low temperatures. Doping with Mn favored the formation of the hexagonal phase at a relative low temperature, as indicated by the phase transition. Strong photoluminescence (in the blue, green, yellow–orange ranges) caused by the doping of various elements in ZnS nanowires and nanobelts, suggested possible applications of the one-dimensional nanostructures in nanoscale optoelectronic devices. [278]
ZnCl2 for ZnO nanowires by AP CVD
Zinc dichloride ZnCl2 in combination with ethanol C2H5OH as oxygen source, has been applied for the growth of ZnO films by atmospheric pressure CVD; the film properties were compared with those grown using Zn/H2O and Zn(acac)2H2O/C2H5OH as precursors (see corresponding sections). Strong green band (GB) emission and a weak near-band-edge (NBE) emission were observed in the RT PL spectrum of the highly c-axis oriented ZnO layer grown on the a -plane sapphire using ZnCl2-C2H5OH precursors. Changing the supply ratio of C2H5OH to ZnCl2 varied only the PL intensity ratio of the GB and NBE emission (pure NBE emission indicating high crystal quality could not be obtained). As was determined by low temperature PL, the precise control of the O/Zn supply ratio is an important factor for defect control and the concentration of the residual impurities. [1 ]
ZnCl2 for ZnO nanowires by AP CVD
ZnCl2 and H2O have been applied as precursors for the growth of single crystalline ZnO nanowires (NWs) on Ni-coated SiO2/Si(100) substrates by atmospheric pressure CVD. The nanowires having diameters 80-700 nm were obtained, NWs were studied by SEM and TEM. The dominant near-band-edge (NBE) emission indicating high crystalline quality the grown ZnO NWs was observed in their PL spectra. [[i]
ZnCl2 for ZnO by spray pyrolysis
ZnCl2 has been used for the growth of ZnO layers and nanorods on glass substrates at 600°C by spray pyrolysis method. Deposited ZnO films were polycrystalline (hexagonal structure) with preferential (002) orientation, with other observed orientations (102), (103) and (004). The films contained hexagonal shaped ZnO rods on the surface. [[ii]]
Zinc chloride ZnCl2 (water or alcoholic 0.05-0.2 mol/l solutions) has been applied as precursor for the growth of ZnO nanostructures (rods, tripods or platelets) by spray pyrolysis on glass, ITO, SnO2 and ZnO-covered glass substrates at temperatures 510-550°C. ZnO rods were grown on glass, while ZnO nanorods were obtained on ITO, SnO2 and ZnO-covered glass using diluted solutions; alcoholic solution result in thinner rods that can be deposited at lower temperature. ZnO hexagonal rods had c-axis orientation with length from some 100 nm to some microns, and diameter from 70 nm to 900 nm. The nanostructures were characterized by SEM and Raman spectricopy; strong and narrow E2 Raman bands indicated that high crystal quality of ZnO rods. [[iii] ]
ZnCl2 for ZnO by ALD
Zinc chloride ZnCl2 has been applied as zinc precursor for the ALE growth of monocrystalline and polycrystalline ZnO thin films, by using a double exchange chemical reaction: ZnCl2 + H2O -> ZnO + 2HCl. Monocrystalline ZnO films were obtained only on GaN/Al2O3 substrates, while on other substrates (sapphire, silicon, or soda lime glass) either 3D growth mode or somewhat c-axis preferably oriented polycrystalline films were obtained. Successful Mn doping of ZnO films using organic Mn precursors was obtained.[[iv]]
ZnCl2 for ZnS by AACVD
Zinc chloride ZnCl2 as Zn precursor, in combination with thiourea or 1,1,3,3-tetramethylthiourea (dissolved in organic solvents) as S precursor, have been applied for the deposition of Zinc sulphide thin films by CADT (AACVD), the results were compared with zinc acetylacetonate (see corresponding Zn(acac)2 section). The volatility and stability of the reactant compounds were studied by TG analysis. Homogeneous ZnS layers having high density (96%) and c-axis oriented hexagonal columnar structure were obtained after growth process optimization. Luminescence was observed for the layers grown at higher temperature (>500°C). The dependence of the growth rate, homogeneity and film density vs. growth temperature, carrier gas flow, nozzle geometry and distance substrate to nozzle, as well as on the solvent and reactant volatility has been studied; the thumb rules for the starting compound selection were determined. [[v]]
ZnCl2 for ZnS by CVD
Early reports of the use of ZnCl2 as precursor for the growth of ZnS thin films by CVD (with H2S as co-reactant) were reviewed in [[vi]]. The issue of using ZnCl2 as precursor is that the residual halide in the films led to rapid burnout and catastrophic breakdown, leading to very short lifetime of the ZnS films.
ZnCl2 for ZnS(Tb) CVD
ZnCl2 has been used as a precursor for the growth of ZnS:Tb thin films by LP CVD. [[vii]](see also TbCl3 section)
ZnCl2 for ZnS ALD
ZnCl2, in combination with H2S as sulphur source, has been aaplied as precursor for growth of polycrystalline ZnS growth by ALE (surface ALE reactions were studied by real-time quadrupole mass spectrometry). The growth was found to be mostly affected by the ZnCl2 desorption and was relatively insensitive to reactant dose.[279]
ZnCl2 for ZnS1-xSex ALD
ZnCl2, in combination with elemental Se and H2S was applied for the growth of polycrystalline ZnS1−xSex thin films by ALE on soda lime substrates by ALD. (see Elemental Se for ZnS1-xSex by ALD section)
[i] Terasako, Tomoaki; Shirakata, Sho, Japanese Journal of Applied Physics, Volume 44, Issue 46, pp. L1410-L1413 (2005). ZnO Nanowires Grown by Atmospheric Pressure Chemical Vapor Deposition Using ZnCl2 and H2O as Source Materials and Their Growth Mechanisms
[ii] Serdar AYDIN, , Güven TURGUT, Mehmet YILMAZ, Mehmet ERTUĞRUL , BEU J SCI & TECHNOL 1 (2011) 1-3, “Fabrication of ZnO nanorods by simplified spray pyrolysis”
[iii] Tatjana Dedova, Malle Krunks, Arvo Mere, Jelena Klauson and Olga Volobujeva, MRS Proceedings 2006 957 : 0957-K10-26 (7 p), DOI: 10.1557/PROC-0957-K10-26, “Preparation of Shape and Size-Controlled Zinc Oxide Nanostructures by Chemical Spray Pyrolysis Technique”
[iv] K.Kopalko, A.Wójcik, M.Godlewski, E.Łusakowska, W.Paszkowicz, J.Z. Domagała, M.M. Godlewski, A. Szczerbakow, K. Świątek, K. Dybko,
physica status solidi (c), Volume 2, Issue 3, pages 1125–1130, February 2005 , “Growth by atomic layer epitaxy and characterization of thin films of ZnO”
[v] F.J. Martin, H. Albers, P.V. Lambeck, G.M.H. Van de Velde, Th.J.A. Popma
Journal of Aerosol Science, Volume 22, Supplement 1, 1991, Pages S435–S438
Luminescent thin films by the chemical aerosol deposition technology (CADT) (AACVD)
[vi] C Yang – PhD.Thesis 1994
http://scholarworks.sjsu.edu/cgi/viewcontent.cgi?article=1880&context=etd_theses
Study of the degradation mechanisms and lifetime optimization of thin film ZnS electroluminescent devices made by MOCVD
[vii] Akiyoshi Mikami, Kousuke Terada, Masaru Yoshida, Shigeo Nakajima Journal of Crystal Growth, Volume 117, Issues 1–4, 2 February 1992, p.991–996
ZnBr2 for ZnO CVD
Zinc dibromide has been reported for the growth of single crystalline ZnO waveguide thin films by CVD on intermediately sputtered ZnO films on sapphire. The minimum loss obtained for the TE0 mode propagating perpendicular to the c axis in a (112¯0) ZnO film was 0.7 dB/cm. [[i]]
ZnBr2 for CdxZn1-xSySe1-y CVD
ZnBr2 has been proposed as potential n-type dopant precursor for the growth of CdxZn1-xSySe1-y layers by MOVPE [[ii]]
[i]Shiosaki, T.; Ohnishi, S.; Kawabata, A., Journal of Applied Physics, Issue Date: May 1979, Volume: 50 Issue:5, p(s): 3113 – 3117 . Optical properties of single‐crystalline ZnO film smoothly chemical‐vapor deposited on intermediately sputtered thin ZnO film on sapphire
[ii] [M Migita, A Taike… - US Patent 5,299,217, 1994
http://www.google.de/patents/US5299217?printsec=description&dq=ZnI2+MOVPE#v=onepage&q=iodide&f=false