scholarly journals Effect of thickness on the optical properties of ZnO thin films prepared by pulsed laser deposition technique (PLD)

2019 ◽  
Vol 15 (32) ◽  
pp. 114-121
Author(s):  
Maysar A. Salim

Zinc Oxide (ZnO) thin films of different thickness were preparedon ultrasonically cleaned corning glass substrate, by pulsed laserdeposition technique (PLD) at room temperature. Since mostapplication of ZnO thin film are certainly related to its opticalproperties, so the optical properties of ZnO thin film in thewavelength range (300-1100) nm were studied, it was observed thatall ZnO films have high transmittance (˃ 80 %) in the wavelengthregion (400-1100) nm and it increase as the film thickness increase,using the optical transmittance to calculate optical energy gap (Egopt)show that (Egopt) of a direct allowed transition and its value nearlyconstant (~ 3.2 eV) for all film thickness (150, 180, 210, and 240)nm, so Zn0 thin films were used as a transparent conducting oxide(TCO) in various optoelectronic application such as a window in athin film solar cells.

2013 ◽  
Vol 734-737 ◽  
pp. 2572-2575 ◽  
Author(s):  
S.B. Chen ◽  
Z.Y. Zhong

Zinc oxide (ZnO) thin films were grown by magnetron sputtering onto glass substrates employing a sintered ceramic target and pure argon gas. The influence of working pressure on structure and optical performance of the thin films were studied by the measurements of X-ray diffraction (XRD) patterns and optical transmission spectra. The optical energy gap of the ZnO thin film were calculated according to the Taucs law. The results demonstrate that all the ZnO thin films have preferred orientation along (002) direction. The working pressure affects not only the structure parameters such as lattice constant, strain and stress in the plane of the film, but also the optical transmittance and energy gap of the ZnO thin films. The ZnO thin film deposited at the working pressure of 0.5 Pa exhibits the maximum average visible transmittance of 86.6%, a compressive stress of 1.72×109 Pa, and an optical energy gap of 3.273 eV.


2015 ◽  
Vol 1109 ◽  
pp. 99-103 ◽  
Author(s):  
K.L. Foo ◽  
U. Hashim ◽  
Chun Hong Voon ◽  
M. Kashif

Transparent semiconductor ZnO thin films deposited on interdigitated electrode (IDE) substrate substrates were obtained by low-cost sol-gel method. The coated ZnO films were annealed in furnace at 500°C for 2 hours. The influence of surface morphologies, crystallization and optical properties was investigated. The structural properties of the annealed ZnO thin films were examined with FESEM and AFM. XRD result shows that all polycrystalline ZnO thin film after annealing have the orientation along the (002) plane. Both FESEM and XRD results revealed that ZnO thin films were composed of hexagonal ZnO crystals in nanoscale dimensions. Moreover, UV-Vis was employed to study the optical properties of the ZnO films. Besides that, the deposited ZnO thin film will further use for pH by I-V curve tracer.


2011 ◽  
Vol 25 (20) ◽  
pp. 2741-2749 ◽  
Author(s):  
J. C. ZHOU ◽  
L. LI ◽  
L. Y. RONG ◽  
B. X. ZHAO ◽  
Y. M. CHEN ◽  
...  

High transparency and conductivity of transparent conducting oxide thin film are very important for improving the efficiency of solar cells. ZnO thin film is a better candidate for transparent conductive layer of solar cell. N-type ZnO thin films were prepared by radio-frequency magnetron sputtering on glass substrates. ZnO thin films underwent annealing treatment after deposition. The influence of the sputtering power on the surface morphology, the electrical and optical properties were studied by AFM, XRD, UV2450 and HMS-3000. The experimental results indicate that the crystal quality of ZnO thin film is improved and all films show higher c-axis orientation with increasing sputtering power from 50 to 125 W. The average transparency of ZnO thin films is higher than 90% in the range of 400–900 nm between the sputtering power of 50–100 W. After the rapid thermal annealing at 550°C for 300 s under N2 ambient, the minimum resistivity reach to 10-2Ω⋅ cm .


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 252 ◽  
Author(s):  
A. M. Alsaad ◽  
A. A. Ahmad ◽  
I. A. Qattan ◽  
Qais M. Al-Bataineh ◽  
Zaid Albataineh

Undoped ZnO and group III (B, Al, Ga, and In)-doped ZnO thin films at 3% doping concentration level are dip-coated on glass substrates using a sol-gel technique. The optical properties of the as-prepared thin films are investigated using UV–Vis spectrophotometer measurements. Transmittance of all investigated thin films is found to attain high values of ≥80% in the visible region. We found that the index of refraction of undoped ZnO films exhibits values ranging between 1.6 and 2.2 and approximately match that of bulk ZnO. Furthermore, we measure and interpret nonlinear optical parameters and the electrical and optical conductivities of the investigated thin films to obtain a deeper insight from fundamental and practical points of view. In addition, the structural properties of all studied thin film samples are investigated using the XRD technique. In particular, undoped ZnO thin film is found to exhibit a hexagonal structure. Due to the large difference in size of boron and indium compared with that of zinc, doping ZnO thin films with these two elements is expected to cause a phase transition. However, Al-doped ZnO and Ga-doped ZnO thin films preserve the hexagonal phase. Moreover, as boron and indium are introduced in ZnO thin films, the grain size increases. On the other hand, grain size is found to decrease upon doping ZnO with aluminum and gallium. The drastic enhancement of optical properties of annealed dip-synthesized undoped ZnO thin films upon doping with group III metals paves the way to tune these properties in a skillful manner, in order to be used as key candidate materials in the fabrication of modern optoelectronic devices.


2013 ◽  
Vol 832 ◽  
pp. 460-465 ◽  
Author(s):  
Nor Diyana Md Sin ◽  
M.H. Mamat ◽  
M. Rusop

The effect of deposition time on properties of ZnO nanostructured thin film was investigated. The ZnO thin films were deposited at various times from 15~75 minutes. The ZnO thin film at 60 min deposition time shows the highest current density and high conductivity with 2.15x10-2 Scm-1. The optical properties of ZnO thin films show high transmittance with >80% at 380 nm to 1200 nm. The thickness of ZnO thin film increases linearly with deposition time. The size of ZnO thin films increase as the deposition time increase. Based from fesem images, the ZnO nanocolumnar structure was formed at 15 to 60 minutes deposition time while at 75 minutes the sample formed nanoflakes structure.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1719-1724
Author(s):  
H. KAVAK ◽  
N. H. ERDOGAN ◽  
K. KARA ◽  
H. YANIS ◽  
Z. BAZ ◽  
...  

The transparent, conductive n and p -type semiconducting ZnO thin films were prepared by pulsed filtered cathodic vacuum arc deposition (PFCVAD) method. The structural, optical and electrical properties of n and p -type ZnO thin films are investigated after annealing at 450°C. 197 nm thick n -type ZnO thin film was deposited with oxygen pressure of 8.5 × 10-4 Torr . XRD pattern of annealed ZnO thin film exhibits hexagonal structure with (100), (101) and (110) orientations. The crystallite size of semiconductor ZnO thin film is 18 nm, interplanar distance 0.16 nm and lattice constant c is 0.52 nm for (110) orientation. The optical transmittance spectra of n and p -type ZnO films are over 90% in the visible wavelength region with optical energy gap 3.3 eV. p -type ZnO thin films are produced by oxidation of PFCVAD deposited zinc nitride. Zinc nitride is deposited with nitrogen pressure of 8.6 × 10-4 Torr and the thickness of this film is 179 nm. The oxidation of zinc nitride thin films at 450°C results in hexagonal structures p -type ZnO thin films. XRD pattern of this film has the same (100), (101) and (110) orientations with the same crystalline structures as the directly deposited ZnO thin film. Hall measurements indicated that ZnO films were p -type and the highest carrier concentration of 1.08 × 1018 cm -3 and mobility of 93.53 cm2/Vs were obtained.


2015 ◽  
Vol 1109 ◽  
pp. 401-404
Author(s):  
I. Saurdi ◽  
Mohamad Hafiz Mamat ◽  
M.F. Malik ◽  
A. Ishak ◽  
Mohamad Rusop

The nanoStructured ZnO thin films were prepared by Spin coating technique on glass substrates at various layers. The structural and optical properties were characterized by field emission scanning electron microscopy (FESEM) and UV-Vis-NIR respectively. The surface morphology reveals that the nanostructured ZnO thin films become densely packed as the thickness increased. The average particles size of ZnO thin film estimated from FESEM images at different layers of 1, 3, 5, 7, 9 were 20nm, 28nm, 36nm, 39nm and 56nm, respectively. The surface roughness of thin films was increase as the thin film thickness increases. The results show all films are transparent in the visible region (400-800 nm) with average transmittance above 85 %. Meanwhile, the optical band gap was decrease as the film thickness increases. The conductivity of ZnO thin film slightly improved as the thickness increased as measured through two probes 1-V measurement system.


2015 ◽  
Vol 33 (3) ◽  
pp. 491-496 ◽  
Author(s):  
Y. Larbah ◽  
M. Adnane ◽  
T. Sahraoui

Abstract Undoped ZnO thin films have been prepared on glass substrates at different substrate temperatures by spray pyrolysis method. The effect of temperature on the structural, morphological and optical properties of n-type ZnO films was studied. The X-ray diffraction (XRD) results confirmed that the ZnO thin films were polycrystalline with wurtzite structure. Scanning electron microscopy (SEM) measurements showed that the surface morphology of the films changed with temperature. The studies demonstrated that the ZnO film had a transmission of about 85 % and energy gap of 3.28 eV at 450 °C. The RBS measurements revealed that ZnO layers with a thickness up to 200 nm had a good stoichiometry.


2020 ◽  
Vol 9 (1) ◽  
pp. 57-65
Author(s):  
Yus Rama Denny Muchtar ◽  
◽  
Teguh Firmansyah ◽  
Adhitya Trenggono ◽  
Danu Wijaya ◽  
...  

This study carried out on the effect of precursor concentration and annealed substrate temperature on the crystal structure, electronic and optical properties of ZnO thin film. An aqueous solution of Acid Nitrite was used as precursors and its concentration was varied from 0.1 M to 0.4 M. The ZnO thin film was deposited on the glass substrate by Spray Pyrolysis Deposition and annealed with different temperature from 300 oC to 600 oC. The crystal structure, electronic and optical properties were investigated by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and UV-Spectrometer. XRD result showed that all thin films have amorphous hexagonal wurtzite crystalline. Particle sizes ranging from 21.83 to 43.67 nm were calculated through Debye-Scherer Method. It showed that the concentration of the precursor had slightly impact on the particle size. Meanwhile, the increase in particle size with increasing annealed temperature is found to be gradual. The average transparent of all thin film was more than 80%. The bandgap of the ZnO thin films was estimated by Tauc Plot Relation. It showed that the bandgap values were increased with the increasing of precursor concentration due to Burstein-Moss Effect. In addition, the decrease in band gap values was found with increasing annealed temperature. Our results demonstrated that the varying precursor concentration and annealed substrate temperature can enhance the structure, electronic and the optical properties of ZnO thin films.


2017 ◽  
Vol 48 ◽  
pp. 211-217 ◽  
Author(s):  
Ji Tao Li ◽  
Ding Yu Yang ◽  
Xing Hua Zhu

ZnO thin films on glass substrates have been successfully fabricated by sol-gel method for various aging time and annealing temperature. X-ray diffraction (XRD) patterns showed the crystallites at (100), (002) and (101) plane of hexagonal wurtzite structure. Atomic force microscope (AFM) images were used to investigate the surface morphology. The transmittance, energy gap, Urbach energy and photoluminescence (PL) of samples were investigated to explore the effects of annealing temperature on optical properties of ZnO thin films under different sol aging time. The transmittance spectra of thin films aged for 24 hours and 48 hours revealed the enhanced transmittance in visible region as rising annealing temperature, also, the optical band gap of the samples increased and Urbach energy decreased. The photoluminescence (PL) spectra of samples aged for 24 hours and 48 hours were studied and found the increased ultraviolet emission at ~387 nm, and various decreased visible emissions with rising annealing temperature. Nevertheless, the excessive sol aging time for 72 hours deteriorated the optical characteristics of thin films, resulting in that transmittance, energy gap and ultraviolet emission declined, and visible emissions increased with rising annealing temperature. The optical performances of the ZnO films aged for different time have no the same dependence of annealing temperature.


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