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Polyelectrolyte-assisted preparation and characterization of nanostructured ZnO thin films

Abstract

The present work focuses on the synthesis and characterization of nanostructured ZnO thin films onto silicon wafers modified by self-assembled-monolayers via chemical bath deposition. Two precursor solutions were designed and used for the film deposition, in which two different polymers were introduced respectively to control the growth of the ZnO colloidal particles in solution. ZnO films were deposited from an aqueous solution containing zinc salt and hexamethylenetetramine (HMTA) in the presence of a graft-copolymer (P (MAA{sub 0.50}-co(MAA-EO{sub 20}){sub 0.50}){sub 70}). A film-formation-diagram was established based on the results obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM), which describes the influence of the concentration of HMTA and copolymer on the ZnO film formation. According to the film morphology, film formation can be classified into three categories: (a) island-like films, (b) uniform films and (c) canyon-like films. The ZnO films annealed at temperatures of 450 C, 500 C, 600 C and 700 C were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). After annealing, the films are polycrystalline ZnO with wurtzite structure. XRD measurements indicate that with increasing annealing temperature, the average grain size increases accordingly and the crystallinity of the films is improved. Upon heating to  More>>
Authors:
Publication Date:
May 15, 2005
Product Type:
Thesis/Dissertation
Report Number:
ETDE-DE-1557
Resource Relation:
Other Information: TH: Diss. (Dr.rer.nat.); Related Information: Max-Planck-Institut fuer Metallforschung, Stuttgart. Berichtv. 165
Subject:
36 MATERIALS SCIENCE; NANOSTRUCTURES; THIN FILMS; SILICON; DEPOSITION; AQUEOUS SOLUTIONS; ZINC OXIDES; PARTICLES; COPOLYMERS; SCANNING ELECTRON MICROSCOPY; ATOMIC FORCE MICROSCOPY; MORPHOLOGY; ANNEALING; X-RAY DIFFRACTION; TRANSMISSION ELECTRON MICROSCOPY; GRAIN SIZE; GRAIN ORIENTATION; SUBSTRATES; LAYERS; PROPANOLS; SOLVENTS; PVP; CRYSTALS; PHOTOLUMINESCENCE; EMISSION SPECTRA; SODIUM HYDROXIDES; COLLOIDS; AMINES; TEMPERATURE RANGE 0400-1000 K; PARTICLE SIZE; INTERFACES; ACETATES; HEXAGONAL LATTICES; TEMPERATURE RANGE 0273-0400 K; ULTRAVIOLET SPECTRA; VISIBLE SPECTRA
OSTI ID:
20841021
Research Organizations:
Stuttgart Univ. (Germany). Fakultaet 3 - Chemie; Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany)
Country of Origin:
Germany
Language:
English
Other Identifying Numbers:
TRN: DE07G2952
Availability:
Commercial reproduction prohibited; OSTI as DE20841021
Submitting Site:
DE
Size:
115 pages
Announcement Date:
Mar 02, 2007

Citation Formats

Jia, Shijun. Polyelectrolyte-assisted preparation and characterization of nanostructured ZnO thin films. Germany: N. p., 2005. Web.
Jia, Shijun. Polyelectrolyte-assisted preparation and characterization of nanostructured ZnO thin films. Germany.
Jia, Shijun. 2005. "Polyelectrolyte-assisted preparation and characterization of nanostructured ZnO thin films." Germany.
@misc{etde_20841021,
title = {Polyelectrolyte-assisted preparation and characterization of nanostructured ZnO thin films}
author = {Jia, Shijun}
abstractNote = {The present work focuses on the synthesis and characterization of nanostructured ZnO thin films onto silicon wafers modified by self-assembled-monolayers via chemical bath deposition. Two precursor solutions were designed and used for the film deposition, in which two different polymers were introduced respectively to control the growth of the ZnO colloidal particles in solution. ZnO films were deposited from an aqueous solution containing zinc salt and hexamethylenetetramine (HMTA) in the presence of a graft-copolymer (P (MAA{sub 0.50}-co(MAA-EO{sub 20}){sub 0.50}){sub 70}). A film-formation-diagram was established based on the results obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM), which describes the influence of the concentration of HMTA and copolymer on the ZnO film formation. According to the film morphology, film formation can be classified into three categories: (a) island-like films, (b) uniform films and (c) canyon-like films. The ZnO films annealed at temperatures of 450 C, 500 C, 600 C and 700 C were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). After annealing, the films are polycrystalline ZnO with wurtzite structure. XRD measurements indicate that with increasing annealing temperature, the average grain size increases accordingly and the crystallinity of the films is improved. Upon heating to 600 C, the ZnO films exhibit preferred orientation with c-axis normal to substrate, whereas the films annealed at 700 C even show a more explicit texture. By annealing at temperatures above 600 C the ZnO film reacts with the substrate to form an interfacial layer of Zn{sub 2}SiO{sub 4}, which grows thicker at elevated annealing temperatures. The ZnO films annealed at 600 C and 700 C show strong UV emission. Another non-aqueous solution system for ZnO thin film deposition was established, in which 2- propanol was used as a solvent and Zn(CH3COO){sub 2}.2H{sub 2}O as well as NaOH as reactants. Polyvinylpyrrolidone (PVP) was used as an additive. The influence of PVP on film formation was investigated by varying the [PVP]/[Zn] ratio. XRD investigations reveal that the films are of ZnO wurtzite structure and consist of nanometer-sized crystals. TEM results indicate that the film growth proceeds by oriented attachment of nanocrystallites from the reaction solution. The room temperature photoluminescence spectra for the as-deposited ZnO thin films shows a strong UV emission and a broad green emission peak. (orig.)}
place = {Germany}
year = {2005}
month = {May}
}