Modulation of Physical Properties of Sprayed ZnO Thin Films by Substrate Temperature for Optical Applications

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650007
Author(s):  
Mohamed Othmane ◽  
Abdallah Attaf ◽  
Hanane Saidi ◽  
Fouad Bouaichi ◽  
Nadia Lehraki ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Substrate Temperature ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Optical Transmittance ◽  
Zno Thin Films ◽  
Zno Films ◽  
Bandgap Energy

We investigated the structural, electrical and optical properties of zinc oxide thin films as the n-type semiconductor. In the present paper, the effect of substrate temperature on the synthesis of ZnO thin films was carried out from 250[Formula: see text]C to 500[Formula: see text]C. ZnO thin films were deposited on glass substrates via ultrasonic spray technique with 0.2[Formula: see text]mol/L of zinc acetate dehydrate. The crystal quality of the thin films was analyzed by X-ray diffraction which results in modified substrate temperature. The optical transmittance and electrical conductivity measurements were carried out by Ultraviolet-visible spectrophotometer and four-point methods, respectively. Polycrystalline films with a hexagonal wurtzite structure with (100) and (002) preferential orientation corresponding to ZnO films were observed at high temperature. The optimal values of the average crystallite size of the ZnO films under consideration are observed beginning with 350[Formula: see text]C of substrate temperature. All films exhibit an average optical transparency of about 85% in the visible region. The shift of optical transmittance toward higher wavelength can be shown by the increase of bandgap energy from 3.245[Formula: see text]eV to 3.281[Formula: see text]eV with increasing substrate temperature of 250–500[Formula: see text]C. The observed Urbach energy of ZnO thin films decreases from 0.11311[Formula: see text]eV to 0.04974[Formula: see text]eV. At a high temperature, the electrical conductivity of ZnO films was increased from [Formula: see text] to 41.58 ([Formula: see text].cm)[Formula: see text] with the increasing substrate temperature from 350[Formula: see text]C to 500[Formula: see text]C.

The Preparation and Optical Property of ZnO Thin-Film by Electrospray

2009 ◽  
Vol 155 ◽  
pp. 151-154 ◽  
Author(s):  
Yan Huai Ding ◽  
Ping Zhang ◽  
Yong Jiang ◽  
Fu Xu ◽  
Jing Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Property ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Zno Thin Films ◽  
Zno Films ◽  
Ultraviolet Region ◽  
Force Microscopy ◽  
Glass Substrates

ZnO thin-films were prepared from sol-gel precursors using electrospray method. The structure, morphology and optical property of ZnO thin-films deposited on glass substrates were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and absorption spectrums (ABS). The surface images obtained directly from AFM showed the compact ZnO films were composed of wurtzite ZnO nanoparticles. The ZnO films presented high optical transmittance in the visible region and strong absorption in ultraviolet region.

Effect of Flexible Substrates on the Structural and Optical Properties of ZnO Films Deposited by Sputtering Method

2015 ◽  
Vol 1107 ◽  
pp. 678-683 ◽  
Author(s):  
Lam Mui Li ◽  
Azmizam Manie Mani ◽  
Saafie Salleh ◽  
Afishah Alias
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Low Cost ◽  
Argon Plasma ◽  
Optical Transmittance ◽  
Zno Thin Films ◽  
Plastic Substrate ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray

Zinc Oxide (ZnO) has attracted much attention because of its high optical transmittance approximately ~80 % with a wide band gap of (3.3 eV at 300 K) and a relatively low cost material. ZnO thin films were deposited on plastic substrate using RF powered magnetron sputtering method. The target used is ZnO disk with 99.99 % purity. The sputtering processes are carried out with argon gas that flow from 10-15 sccm. Argon is used to sputter the ZnO target because the ability of argon that can remove ZnO layer effectively by sputtering with argon plasma bombardment. The deposited ZnO thin films are characterized using X-Ray Diffraction (XRD) and UV-Vis Spectrometer. The analysis of X-ray diffraction show that good crystalline quality occurs at nominal thickness of 400 nm. The optical studies showed that all the thin films have high average transmittance of approximately 80 % and the estimated value of optical band gap is within 3.1 eV-3.3 eV range.

Electrical Properties of Pulsed Laser Deposited ZnO Thin Films

2009 ◽  
Vol 67 ◽  
pp. 121-125
Author(s):  
Chattopadhyay Sourav ◽  
Kumar Nath Tapan
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Hall Mobility ◽  
Pulsed Laser ◽  
Deposition Process ◽  
Zno Thin Films ◽  
Zno Films ◽  
Visible Absorption ◽  
Substrate Temperatures

Epitaxial Single-crystal ZnO thin films have been grown on c-plane (0001) sapphire by Pulsed Laser Deposition process at different substrate temperatures (300 – 800 °C) with 10-1 mbar oxygen pressure. The thicknesses of the films have been varied by varying number of pulses with a repetition rate of 10 pulse/sec. It is found that the sheet resistivity of ZnO thin films grown on c-plane sapphires are in the order of 10-2 Ω-cm and it increases with increasing substrate temperatures and film thickness. The carrier concentrations and Hall mobility are found to be in the order of 1017 cm-3 and ~195 cm2/V-s, respectively. The Hall mobility slightly decreases with increase of substrate temperature and thickness of the films. It is also found that the ZnO films are structurally uniform and well oriented with perfect wurtzite structure with c/a ratio 5.1. We have also deposited non-epitaxial ZnO films on (100) p-Silicon substrates at the same conditions. From HR FE-SEM micrographs, surface morphology of ZnO films grown at lower substrate temperature are found to be uniform compared to the films grown at higher temperatures showing non-uniformity and misoriented wurtzite structures. However, the surface morphology of ZnO flims grown epitaxially on (0001) sapphire are found to be more uniform and it does not change much with growth temperature. The resistivity of the films grown on p-Silicon at higher temperatures is in the order of 103 Ω-cm whereas films grown at lower substrate temperatures show comparatively lower resistivities (~ 102 Ω-cm). From the recorded UV-Visible absorption spectrum the band gap of the film has been estimated to be 3.38 eV.

Structural and Optical Studies of Molarity Based ZnO Thin Films

2017 ◽  
Vol 17 ◽  
pp. 140-148 ◽  
Author(s):  
A. Jacquiline Regina Mary ◽  
S. Arumugam
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Visible Region ◽  
Precursor Solution ◽  
Hexagonal Wurtzite Structure ◽  
Solution Concentration ◽  
Molar Concentration ◽  
Zno Thin Films ◽  
Zno Films ◽  
Average Grain Size

Zinc Oxide thin films were prepared for different precursor solution molarities from 0.025M to 0.1M by spray pyrolysis deposition technique. A comprehensive study was carried out to realize the effect of concentration of precursor on ZnO thin films. The optimized temperature of the glass substrate was 300°C. From the XRD data it is inferred that the films are polycrystalline and hexagonal wurtzite structure . The degree of preferred orientation were along diffraction planes (100), (002) and (101) for all the ZnO films. The intensity of the diffraction peak prepared with 0.1M concentration is higher than those prepared at lower concentrations. The grain size (D) was calculated using Debye-Scherrer formula. It was found that the average grain size increases, when the molar concentration increases. As the solution concentration increases, the band gap decreases. The films are transparent in the visible region (85%), and the transmittance decreases as the molar concentration increases, which is caused by optical scattering at grain boundaries.

TRANSPARENT ZINC OXIDE THIN FILMS PREPARED BY PLD WITH DIFFERENT OXYGEN PRESSURES

2007 ◽  
Vol 14 (03) ◽  
pp. 425-429
Author(s):  
KASIMAYAN UMA ◽  
MOHAMAD RUSOP ◽  
TETSUO SOGA ◽  
TAKASHI JIMBO
Keyword(s):  
Thin Films ◽  
Oxygen Pressure ◽  
Visible Region ◽  
Optical Transmittance ◽  
Xrd Analysis ◽  
Zno Thin Films ◽  
Axis Orientation ◽  
Glass Substrates ◽  
High Oxygen Pressure ◽  
High Pressure Oxygen

ZnO thin films were prepared on silicon (001) and corning glass substrates using Pulsed laser deposition (PLD) technique with different oxygen pressures. The microstructure, crystallinity, and resistivity of the films depend on the oxygen pressure used. The effects of the films grown at room temperature and at 500°C with different oxygen pressures have been investigated by analyzing the optical and electrical properties of the film. The XRD analysis showed that the high intensity of c-axis orientation of ZnO thin films was obtained under high oxygen pressure and this leads to greater electrical and optical properties. By applying high pressure oxygen, the resistivity value was decreased and optical transmittance became higher in the visible region. The surface morphology of the films showed that the smooth surface was observed without any cracks.

Effect Co- and Sc- Doping on the Functional Properties of Nanocrystalline Powders and Thin Films of ZnO

2010 ◽  
Vol 1256 ◽  
Author(s):  
Marco A Galvez ◽  
Oscar Perales-Perez ◽  
Surinder P Singh
Keyword(s):  
Thin Films ◽  
Crystallite Size ◽  
Sol Gel ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Oxide Phase ◽  
Nanocrystalline Powders ◽  
Zno Films ◽  
Exciton Peak ◽  
Doped Zno

AbstractA modified sol-gel approach to synthesize well-crystallized pure and doped ZnO nanocrystalline powders and thin films has been developed. The attachment of ZnO films onto quartz substrates was optimized by selecting suitable organic agents to control the viscosity of precursor solutions. Thermo-gravimetric analyses on pure and doped precursor solids suggested the need for annealing temperatures above 400 °C to assure the effective crystallization of the oxide phase. The average crystallite size in powders and thin films varied from 25.9 nm to 33.7 nm when pure ZnO films were annealed for 1 hour in the 450 °C - 600 °C range. The average crystallite size ranged between 30 nm and 33 nm in the presence of cobalt (5 at%) and decreased from 33.7 nm to 21.1 nm when scandium ions was used in the 0.0 at% - 10 at% range under similar annealing conditions. UV-vis measurements showed a sharp exciton peak centered at 370 nm whereas photoluminescence analyses detected the characteristic ZnO emission band in the UV region. No photoluminescence band in the visible region, usually attributed to defect states in ZnO, was observed in our measurements. Magnetization measurements revealed a weak ferromagnetism in Co-doped ZnO whereas a clear diamagnetism was evident in the Sc-doped sample.

INFLUENCE OF POST ANNEALING ON SOL–GEL DEPOSITED ZnO THIN FILMS

2014 ◽  
Vol 21 (04) ◽  
pp. 1450046 ◽  
Author(s):  
HEMALATA BHADANE ◽  
EDMUND SAMUEL ◽  
DINESH KUMAR GAUTAM
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Zno Thin Films ◽  
Nanocrystalline Films ◽  
Post Annealing ◽  
Deposited Films ◽  
Lower Resistivity

The effect of annealing temperature on sol–gel deposited ZnO thin films have been studied. The average crystallite size determined from XRD shows that the deposited films are nanocrystalline. FTIR confirms deposition of ZnO thin films. The transmittance of annealed ZnO thin films is greater than 80% in visible region with bandgap ranging from 3.25–3.19 eV. The films annealed at 450°C temperature shows lower resistivity value of 527.241 Ωm. The deposited nanocrystalline films are suitable for biosensing applications due to its higher surface area.

EFFECTS OF Ge DOPING THROUGH ION IMPLANTATION ON THE STRUCTURAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS PREPARED BY SOL-GEL TECHNIQUE

2007 ◽  
Vol 21 (31) ◽  
pp. 5257-5263 ◽  
Author(s):  
S. W. XUE ◽  
X. T. ZU ◽  
X. XIANG ◽  
M. Y. CHEN ◽  
W. G. ZHENG
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Ion Implantation ◽  
Deep Level ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Zno Films ◽  
Near Band Edge ◽  
Structural And Optical Properties

ZnO thin films were first prepared by the sol–gel process, and then Ge ions were implanted into the ZnO films. The effects of ion implantation on the structural and optical properties of the ZnO films were investigated by X-ray diffraction, photoluminescence (PL), and optical transmittance measurements. Measurement results showed that the intensity of the (002) diffraction peak was decreased and the full width at half maximum was narrowed. PL emission was greatly extinguished after Ge ion implantation. Both the near band edge (NBE) excitonic UV emission at 391 nm and the defect related deep level emission centered at 470 nm in the visible region were decreased after Ge ion implantation. NBE peak and the absorption edge were observed to have a blueshift toward higher energy.

scholarly journals Synthesis and Characterization of Molybdenum Doped ZnO Thin Films by SILAR Deposition Method

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
R. Radha ◽  
A. Sakthivelu ◽  
D. Pradhabhan
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Dopant Concentration ◽  
Blue Shift ◽  
Zno Thin Films ◽  
Zno Films ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
Mo Doping ◽  
Doped Zno

<em>Molybdenum (Mo) doped zinc oxide (ZnO) thin films were deposited on the glass substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) deposition method. The effect of Mo dopant concentration of 5, 6.6 and 10 mol% on the structural, morphological, optical and electrical properties of n-type Mo doped ZnO films was studied. The X-ray diffraction (XRD) results confirmed that the Mo doped ZnO thin films were polycrystalline with wurtzite structure. The field emission scanning electron microscopy (FESEM) studies shows that the surface morphology of the films changes with Mo doping. A blue shift of the optical band gap was observed in the optical studies. Effect of Mo dopant concentration on electrical conductivity was studied and it shows comparatively high electrical conductivity at 10 mol% of Mo doping concentration. </em>

Effects of Thickness and Preheated Temperature on Grains Orientation of 2D-ZnO Nanostructure and their Photocatalytic Activity

2021 ◽  
Vol 66 ◽  
pp. 113-128
Author(s):  
Mahdia Toubane ◽  
Assia Azizi ◽  
D. Houanoh ◽  
R. Tala-Ighil ◽  
F. Bensouici ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Heating Temperature ◽  
Optical Transmittance ◽  
Zno Thin Films ◽  
Visible Range ◽  
Zno Films ◽  
Blue Dye ◽  
Zno Nanostructure ◽  
Number Of Layers

The effects of pre-heating temperature and thickness of layers on (002) preferred orientation of ZnO thin films and their photocatalytic activity are reported. All films crystallize into a Zincite-type structure. With increasing pre-heating temperature, the evolution from (002) to (101) diffraction peaks indicates change in growth mode of ZnO films. Pre-heating at 100°C is the most favourable for highly oriented ZnO thin films along (002) plane whereas all films deposited with different number of layers are oriented along (101) plane. The crystallite size is found to be in the range 20 - 32 nm. The observed average optical transmittance for these films is higher than 90% in the visible range. The energy band gap decreases with increasing number of layers but increases with increasing pre-heating temperatures. Wettability tests of ZnO thin films surface show a hydrophobic aspect for all films. The film pre-heated at 400°C with 223nm of thickness exhibits the highest degradation of methyl blue dye of 94% with high levels of photostability over five cycles.

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