Growth of the Sol-Gel Based ZnO:Al Thin Films with High Doping Concentration

2012 ◽  
Vol 485 ◽  
pp. 144-148
Author(s):  
Jian Lin Chen ◽  
Yan Jie Ren ◽  
Jian Chen ◽  
Jian Jun He ◽  
Ding Chen

Preferentially oriented Al-doped ZnO thin films with doping concentration of 1, 2, 3, 5 and 10 mol% respectively were prepared on glass substrates via sol-gel route. The crystallinity of films was characterized by X-ray diffraction and the surface morphologies were observed by scanning electron microscopy. The results show that ZnO:Al films at low doping concentration (1, 2 mol%) grow into dense homogenous microstructure. However, as for high doping concentration (3, 5, 10 mol%), Al3+ precipitate in the form of amorphous Al2O3 and ZnO:Al films exhibit heterogeneous nucleation and exceptional growth of the big plate-like crystals at the interface of the amorphous Al2O3 and ZnO:Al matrix.

2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz

AbstractThis paper describes the growth of Cd doped ZnO thin films on a glass substrate via sol-gel spin coating technique. The effect of Cd doping on ZnO thin films was investigated using X-ray diffraction (XRD), UV-Vis spectroscopy, photoluminescence spectroscopy, I–V characteristics and field emission scanning electron microscopy (FESEM). X-ray diffraction patterns showed that the films have preferred orientation along (002) plane with hexagonal wurtzite structure. The average crystallite sizes decreased from 24 nm to 9 nm, upon increasing of Cd doping. The films transmittance was found to be very high (92 to 95 %) in the visible region of solar spectrum. The optical band gap of ZnO and Cd doped ZnO thin films was calculated using the transmittance spectra and was found to be in the range of 3.30 to 2.77 eV. On increasing Cd concentration in ZnO binary system, the absorption edge of the films showed the red shifting. Photoluminescence spectra of the films showed the characteristic band edge emission centred over 377 to 448 nm. Electrical characterization revealed that the films had semiconducting and light sensitive behaviour.


2017 ◽  
Vol 05 (01) ◽  
pp. 1750004
Author(s):  
R. Vettumperumal ◽  
S. Kalyanaraman ◽  
R. Thangavel

Nanocrystalline ruthenium (Ru)-doped ZnO thin films on sapphire substrate was prepared using sol–gel method by spin coating technique. The structural and I-V characteristics of Ru doped ZnO thin films were studied from the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) analysis and Raman spectroscopy. X-ray diffraction (XRD) results revealed that the deposited films belonged to hexagonal wurtzite structure with c-axis orientation. It is also confirmed from the Raman spectra. Enhancement of longitudinal optical (LO) phonon is observed by the strong electron–phonon interaction. An observed increment in sheet resistance with increase in dopant percentage of Ru (1–2[Formula: see text]mol%) in ZnO films was found and better I-V characteristic behavior was observed at 1[Formula: see text]mol% of Ru-doped ZnO thin films. Trap limited current flow inside the material was calculated from the log I versus log V plot in the higher voltage region.


2012 ◽  
Vol 430-432 ◽  
pp. 310-314 ◽  
Author(s):  
Wei Wang ◽  
Wei Meng ◽  
Ming Hui Liu ◽  
Xin Bo Wang

Na-doped ZnO thin films were deposited on microscope glass substrates by sol-gel spin coating method, the Na/Zn ratio were 0at.%, 5at.%, 7.5at.%, 10at.%, 15at.%. The crystal structures, surface morphology, and optical properties were analyzed by X-ray diffraction, scanning electron microscopy, ultraviolet–visible spectrophotometer, respectively. The results show that all the films are preferentially oriented along the c-axis perpendicular to the substrate surface. With the increase of the doping concentration, the roughness of the surfaces decrease and grain size grows from 17.1nm to 21.7nm, the sample with 10at.% Na exhibits best crystallinity and has lowest strain along the c-axis. The average optical transparency of the samples is higher than 70%, optical band gaps are between 3.213eV and 3.289eV.


2012 ◽  
Vol 151 ◽  
pp. 314-318
Author(s):  
Ching Fang Tseng ◽  
Cheng Hsing Hsu ◽  
Chun Hung Lai

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various preheating temperatures and annealing temperatures. Particular attention will be paid to the effects of a thermal treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of treatment film were examined by scanning electron microscopy and atomic force microscopy. At a preheating temperature of 300oC and an annealing temperature of 700oC, the MgAl2O4 films with 9 μm thickness possess a dielectric constant of 9 at 1 kHz and a dissipation factor of 0.18 at 1 kHz.


2010 ◽  
Vol 638-642 ◽  
pp. 2915-2920
Author(s):  
Bajirao K. Sonawane ◽  
Mukesh P. Bhole ◽  
Dnyaneshwar S. Patil

Single crystalline a-axis Mg doped ZnO thin films (MgxZn1-xO) were successfully prepared by sol-gel spin coating method using Zinc acetate, Magnesium acetate as precursors with ethanol as a solvent. The prepared solutions were used to deposit the films on silicon (100) substrate for different mole concentrations (x = 0.1 to 0.33). All deposited films were annealed at 450 0C to get dense crystalline films. X-ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Analysis by X-ray (EDAX), Fourier Transform Infrared Spectroscopy (FTIR), Ellipsometry and semiconductor characterization system with probe station were used to characterize the deposited films for structural, chemical, optical, mechanical and electrical properties. The intense absorption peak was observed in the IR spectra for all deposited films showing bond position of fundamental ZnO peak for all Mg mole concentrations. From the XRD spectra, it revealed that the deposited films were single crystalline and a-axis oriented. EDAX spectra clearly showed the peak of Mg along with Zn and O indicating the successful incorporation of Mg into the ZnO. The refractive index was successfully tailored from 1.6 to 1.11 corresponding to 0.1 to 0.33 Mg mole concentration. The refractive index was found to be decrease with an increase in Mg mole concentration. I-V characteristics shows decrease in current with increase in the Mg mole concentration. Significant effect was not observed on thickness of deposited films due to the varying Mg mole fraction. Through SEM image, it was noted that the uniform film of Mg doped ZnO was deposited on the silicon substrate. Our results explore the applicability of MgZnO as cladding layer material to form effective and efficient heterostructure with ZnO as an active layer for the optical wave-guide applications.


Author(s):  
Tran Thi Ngoc Anh ◽  
Tran Thi Ha ◽  
Nguyen Viet Tuyen ◽  
Pham Nguyen Hai

This paper presents results of preparation of Ag doped ZnO bulk sample by solid state reaction and Ag doped ZnO thin films by sputtering method. Effect of doping concentration (1, 2 and 4%) on the properties of the thin films was investigated. Various methods were utilized to investigate characteristics of the samples: X-ray diffraction, Raman scattering spectroscopy, photoluminescence, energy dispersive X-Ray spectroscopy, scanning electron microscopy, atomic force microscope, absorption spectroscopy and Hall measurement. The results show that Ag diffused into ZnO crystal lattice after heat treatment at 1200oC. As-prepared thin film samples exhibit low resistivity in the order of 10-3Ω.cm. The film doped with 2% Ag shows the lowest resistivity of 1.8´10-3Ω.cm which is potential for making transparent electrodes in optoelectronics.


Author(s):  
Ali sadek Kadari ◽  
Abdelkader Nebatti Ech-Chergui ◽  
Mohamed walid Mohamedi ◽  
Abdelhalim Zoukel ◽  
Tair Sabrina ◽  
...  

Abstract Pure and Al-doped ZnO thin films were successfully deposited with sol-gel dip coating on both substrates Si (100) and glass. The structural, chemical, morphological and optical properties as a function of the annealing temperature and dopant atomic concentration were investigated by means of X-ray diffraction, Energy dispersive X-ray, Scanning Electron Microscopy, and spectrophotometry. All the pure and doped films show a polycrystalline nature and hexagonal in structure. Accurate doping was proven by EDX. In addition, the SEM analysis revealed that the films possess uniform distribution throughout the surface and the grain dimension decreases with Al doping. From the transmittance measurements, it is see that all films are over 55% in the visible region and the band gap energy increases from 3.28 to 3.45 eV with the increase of Al concentration.


2010 ◽  
Vol 24 (31) ◽  
pp. 6079-6090 ◽  
Author(s):  
I. I. RUSU ◽  
M. SMIRNOV ◽  
G. G. RUSU ◽  
A. P. RAMBU ◽  
G. I. RUSU

Zinc oxide ( ZnO ) thin films were deposited onto glass substrates by d.c. magnetron sputtering. The structural analysis, by X-ray diffraction and atomic force microscopy, indicate that the studied films are polycrystalline and have a wurtzite (hexagonal) structure. The film crystallites are preferentially oriented with (002) planes parallel to the substrates. The mechanism of electronic transport is explained in terms of Seto's model elaborated for polycrystalline semiconducting films (crystallite boundary trapping theory). Some parameters of used model (impurity concentration, density and energy of the trapping states, etc.) have been calculated. The optical bandgap (Eg0 = 3.28–3.37 eV ) was determined from absorption spectra.


Author(s):  
Marimuthu Karunakaran ◽  
S. Maheswari ◽  
Kasinathan Kasirajan ◽  
Sivaji Dinesh Raj ◽  
Rathinam Chandramohan

The growth of highly textured Mn doped Zinc oxide (ZnO) thin films with a preferred (002) orientation has been reported by employing successive ionic layer growth by adsorption reaction (SILAR) using a sodium zincate bath on glass substrates has been reported. The prepared films were characterized by X-ray diffraction (XRD), optical spectroscopy and scanning electron microscopy (SEM) measurement. The XRD analysis reveals that the films were polycrystalline. Morphology of the films was found to be uniform with smaller grains and exhibits a structure with porous. The calculated Band gap value was found to be 3.21 eV prepared at 15 mM MnSO4 concentration.


2007 ◽  
Vol 124-126 ◽  
pp. 339-342
Author(s):  
Gun Hee Kim ◽  
Hong Seong Kang ◽  
Dong Lim Kim ◽  
Hyun Woo Chang ◽  
Byung Du Ahn ◽  
...  

Cu-doped ZnO (denoted by ZnO:Cu) films have been prepared by pulsed laser deposition using 3 wt. CuO doped ZnO ceramic target. The carrier concentrations (1011~1018 cm-3) and, electrical resistivity (10-1~105 cm) of deposited Cu-doped ZnO thin films were varied depending on deposition conditions. Variations of electrical properties of Cu-doped ZnO indicate that copper dopants may play an important role in determining their electrical properties, compared with undoped films. To investigate effects of copper dopants on the properties of ZnO thin films, X-Ray diffraction (XRD), photoluminescence (PL), and Hall measurements have been performed and corresponded.


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