scholarly journals Investigation on Al Doped Zno Thin Films and its N-Alzno/P-Si Junction Diodes Via Dip Coating and JNSP Techniques

2018 ◽  
Vol 34 (5) ◽  
pp. 2590-2596
Author(s):  
S. Kalidass ◽  
P. Thirunavukkarasu ◽  
M. Balaji ◽  
J. Chandrasekaran

From this investigation, we find out that the dip coating and jet nebulizer spray pyrolysis (JNSP) techniques are the suitable to fabricate aluminum doped zinc oxide (AlZnO) thin films and the P-N junction diode of n-AlZnO/p-Si at 450°C. Several characterization techniques are used to measure the consequences of Al doping (0, 0.5, 1.0, 1.5, 2.0 and 2.5 wt.%) on structural, optical, electrical and diode properties of ZnO. We recorded that the films were polycrystalline with a hexagonal structure of ZnO by the X-ray diffraction (XRD) analysis. The disparities of the sub-micro sized rod-like structures are observed from the scanning electron microscope (SEM) images. The energy dispersive X-ray spectroscopy (EDX) analysis proved that the elements of Al, Zn and O were presented in the film. The absorbance and band gap energy (Eg) values were ascertained from the ultraviolet visible (UV-vis) analysis. By the current-voltage (I-V) characterization, the maximum conductivity value is detected for 1.5 wt.% of Al doped ZnO film. The I-V measurement for finding the diode parameters of ideality factor (n) and barrier height (Fb) in dark and under light was taken.

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.


Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.


Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 395 ◽  
Author(s):  
Víctor Herrera ◽  
Tomás Díaz-Becerril ◽  
Eric Reyes-Cervantes ◽  
Godofredo García-Salgado ◽  
Reina Galeazzi ◽  
...  

Tantalum-doped ZnO structures (ZnO:Ta) were synthesized, and some of their characteristics were studied. ZnO material was deposited on silicon substrates by using a hot filament chemical vapor deposition (HFCVD) reactor. The raw materials were a pellet made of a mixture of ZnO and Ta2O5 powders, and molecular hydrogen was used as a reactant gas. The percentage of tantalum varied from 0 to 500 mg by varying the percentages of tantalum oxide in the mixture of the pellet source, by holding a fixed amount of 500 mg of ZnO in all experiments. X-ray diffractograms confirmed the presence of zinc oxide in the wurtzite phase, and metallic zinc with a hexagonal structure, and no other phase was detected. Displacements to lower angles of reflection peaks, compared with those from samples without doping, were interpreted as the inclusion of the Ta atoms in the matrix of the ZnO. This fact was confirmed by energy dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD) measurements. From scanning electron microscopy (SEM) images from undoped samples, mostly micro-sized semi-spherical structures were seen, while doped samples displayed a trend to grow as nanocrystalline rods. The presence of tantalum during the synthesis affected the growth direction. Green photoluminescence was observed by the naked eye when Ta-doped samples were illuminated by ultraviolet radiation and confirmed by photoluminescence (PL) spectra. The PL intensity on the Ta-doped ZnO increased from those undoped samples up to eight times.


2019 ◽  
Vol 17 (12) ◽  
pp. 987-990
Author(s):  
K. Rathi Devi ◽  
G. Selvan ◽  
M. Karunakaran ◽  
G. Rajesh Kanna ◽  
K. Kasirajan

In this work, Mn doped Zinc Oxide (ZnO) thin films were coated onto glass substrates by low cost SILAR technique by altering dipping cycle such as 40, 60, 80 and 100. The film thickness was estimated using weight gain method and it revealed that the film thickness increased with dipping cycle. The structural, morphological, elemental and FTIR properties of the coated Mn doped ZnO films were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), EDAX and FTIR spectrophotometer respectively. The prepared films were found to be hexagonal structure with polycrystalline in nature with preferential orientation along (002) plane. X-ray line profile analysis was used to evaluate the micro structural parameters. The crystallite size values are increased with increase of dipping cycle. Morphological results showed that the dipping cycle has a marked effect on morphology of the prepared Mn doped ZnO thin films. EDAX studies showed that the presence of Zinc, Oxygen and Mn content.


2020 ◽  
Vol 234 (2) ◽  
pp. 355-379 ◽  
Author(s):  
R. Marnadu ◽  
J. Chandrasekaran ◽  
P. Vivek ◽  
V. Balasubramani ◽  
S. Maruthamuthu

AbstractInter-connected network grains of tungsten trioxide (WO3) thin films were deposited on glass using a jet nebulizer spray pyrolysis (JNSP) technique by varying the substrate temperature at 350, 400, 450 and 500 °C. Phase transformation (monoclinic to orthorhombic) was observed during the film growth through X-ray diffraction (XRD) analysis. Field emission scanning electron microscope (FE-SEM) images revealed a better grain growth with smooth surface for 400 °C. The WO3 film deposited at 400 °C exhibits minimum band gap and maximum optical conductivity of 3.2 eV and 5.8 × 1014 (Ω.cm)−1. From the current-voltage (I–V) characteristics, the mean electrical conductivity is found to increase gradually and the activation energy reduced at higher substrate temperature. Cu/WO3/p–Si structured Schottky barrier diodes (SBDs) have been fabricated with different substrate temperature and it was tested under variable device temperatures ranging from 30 to 170 °C. The experimental results of all SBDs indicated a linear reduction in the ideality factor (n) with a small increment in effective barrier height (ΦB) with increase in device temperature, which is due to lateral inhomogeneity’s at the interface. Moreover, the minimum n value of 2.89 and their corresponding ΦB of 0.71 eV were recorded for device temperature at 170 °C. Compared with other SBDs, the device fabricated at 400 °C demonstrated a better thermal stability and device performance.


2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
E. Penilla ◽  
J. Wang

Nitrogen-rich titanium nitride (TiN) thin films containing excess nitrogen up to 87.0 at.% were produced on (100) Si substrates via the reactive magnetron DC-sputtering of a commercially available 99.995 at.% pure Ti target within an argon-nitrogen (Ar-N2) atmosphere with a 20-to-1 gas ratio. The process pressure (PP) and substrate temperature (TS) at which deposition occurred were varied systematically between 0.26 Pa–1.60 Pa and between15.0∘C–600∘C, respectively, and their effects on the chemical composition, surface morphology, and preferred orientation were characterized by energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). The EDS analysis confirms increasing nitrogen content with increasingPPandTS. The SEM images reveal a uniform and crystallized surface morphology as well as a closely packed cross-sectional morphology for all crystalline films and a loosely packed cross-sectional morphology for amorphous films. Films produced at lowerPPandTShave a pyramidal surface morphology which transitions to a columnar and stratified structure asPPandTSincrease. The XRD analysis confirms the existence of only theδ-TiN phase and the absence of other nitrides, oxides, and/or sillicides in all cases. It also indicates that at lowerPPandTS, the preferred orientation relative to the substrate is along the (111) planes, and that it transitions to a random orientation along the (200), (220), and (311) planes asPPandTSincrease and these results correlate with and qualify those observed by SEM.


2015 ◽  
Vol 1109 ◽  
pp. 181-185 ◽  
Author(s):  
Mohd Firdaus Malek ◽  
Mohamad Hafiz Mamat ◽  
M.Z. Musa ◽  
M. Rusop

Multilayered thin films of aluminum-doped ZnO (Al:ZnO) have been deposited by the sol-gel dip coating technique. Experimental results indicated that the thermal annealing temperature affected the crystallinity of the Al:ZnO films. X-ray diffraction (XRD) analysis showed that thin films were preferentially orientated along the c-axis plane. The preferred orientation along (0 0 2) plane becomes more pronounced as the thermal annealing being increased. The film thickness ranges between 180 and 690 nm. In our experiments, the most optimum condition of Al:ZnO annealing temperature was both 500 oC.


2013 ◽  
Vol 20 (05) ◽  
pp. 1350047 ◽  
Author(s):  
QIAN FENG ◽  
DONGYAN TANG ◽  
ZAIQIAN YU ◽  
SHUO GU ◽  
ENYING JIANG

In this paper, stearic acid/ Zn2+ monolayer were formed at air–water interface and then multilayers were deposited onto a glass slide by Langmuir–Blodgett method. After annealing at 300°C for 0.25 h and 550°C for 2 h, ZnO thin films were fabricated. The optimized parameters for monolayer formation and multilayers deposition were determined by the surface pressure-surface area (Π-A) isotherm and transfer ratio (t.r.), respectively. The results of X-ray diffraction showed that multilayers changed into ZnO thin films with hexagonal structure and of high crystallization after annealing at high temperature. The observation of SEM images indicated that ZnO thin films had a uniform and flat surface with compact arrangement.


2013 ◽  
Vol 341-342 ◽  
pp. 237-241
Author(s):  
Wei Hua Huang ◽  
Guo Wen Zhong ◽  
Li Ping Su ◽  
Tan Li

Pure and Al-doped ZnO thin films were deposited by radio frequency magnetron sputtering at room temperature on n-(100) Si, fused quartz and Pt/Ti/SiO2/Si substrates. Structural, optical and electrical properties of the prepared thin films had been characterized. The X-ray diffraction results indicated that all the films had (002) preferential orientation. The AFM and SEM images showed that the surface of the films was smooth, crack-free and pore-free, the interface between the film and the substrate was sharp and distinct. From the transmission data the band gap energy Eg of the film increased when doped with Al2O3, and the transparent was still high (above 80%). The current voltage characteristics indicated that doping with Al2O3, the leakage current of ZnO thin films increased rapidly and the films acted as a conductive.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
R. Mariappan ◽  
V. Ponnuswamy ◽  
P. Jayamurugan ◽  
R. N. Jayaprakash ◽  
R. Suresh

thin films have been deposited on glass substrates at substrate temperature 400°C through nebulizer spray pyrolysis technique. X-ray diffraction (XRD) analysis shows that the films structure is changed from hexagonal to tetragonal. The high-resolution scanning electron microscopy (HRSEM) studies reveal that the substrate is well covered with a number of grains indicating compact morphology with an average grain size 50–79 nm. Energy dispersive X-ray analysis (EDAX) reveals the average ratio of the atomic percentage. Optical transmittance study shows the presence of direct transition. Band gap energy decreases from 3.33 to 2.87 eV with respect to the rise of Sn content. The electrical resistivity of the thin films was found to be 106 Ω-m.


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