N. Ameera

Effects of Pressure Dependence on Nanocolumnar Zinc Oxide Deposited by RF Magnetron Sputtering

Nanocolumnar zinc oxide (ZnO) was deposited on glass substrates by RF magnetron sputtering.It was performed with a ZnO target at RF power of 200 W. The deposition wascarried out in argon and oxygen ambient at the ratio of 10 and 5 sccmrespectively, with total deposition time of 1 hour. The growth temperature wasfixed at 500°C and deposition pressure specified at 3, 5 and 10 mTorr. It wasobserved that the morphological and photoluminescence properties of ZnOstrongly dependent on the deposition pressure. The ZnO mean grain area was inverselyrelated with the surface roughness. The best morphological andphotoluminescence properties was found to be associated with ZnO grown at 10mTorr. Smooth ZnO surface and lowest defects related emission in PL wasobtained for the respective sample.

Study of Annealed Nickel (Ni)/Indium Tin Oxide (ITO) Nanostructures Prepared by RF Magnetron Sputtering

Nickel (Ni) / indium tin oxide (ITO) nanostructures were deposited on glass and silicon (111) substrates by RF magnetron sputtering using a nickel target and ITO (In-Sn, 90%-10%) targets. The post-deposition annealing has been performed for Ni/ITO films in air and the effect of annealing temperature on the electrical, optical and structural properties on ITO films was studied. We found the appearance of (411) and (622) peaks in addition to (400) and (222) major peaks, which indicates an improvement of the film crystallinity at high annealing temperature of 650°C. The samples show higher transmittance of more than 90% at 460 nm after annealing. In addition, increasing the annealing temperatures also improve the film electrical properties. The resistivity decreases to 6.67×10-6 Ωcm when annealed at 500°C as opposed to 6.75×10-5 Ωcm in as-deposited film.

Structural and Optical Properties of Nickel (Ni)/indium Tin Oxide (ITO) Thin-Films Deposited by RF Magnetron Sputtering

Nickel (Ni)/ indium tin oxide (ITO) thin-films have been deposited on silicon (Si) and glass substrates using radio-frequency (RF) magnetron sputtering at 200°C temperature. ITO layer was deposited on top of Ni layer with various deposition parameter. The material and optical properties of the ITO samples with and without Ni seed layer were analyzed. X-ray diffraction studies shows that the films are crystalline with the typical ITO diffraction peaks of (222), (400) and (411). The FESEM and AFM images shows that the grains have uniform shapes and sizes. FESEM results reveal that the grain size along the sample surface decreases when the Ni seed layer is added. Both the samples shows higher transmittance of more than 95% in UV-vis spectrometer.

Structural and Optical Properties of Nickel-Doped Zinc Oxide Thin Film on Nickel Seed Layer Deposited by RF Magnetron Sputtering Technique

Nickel (Ni)-doped zinc oxide (ZnO) layers were deposited simultaneously by radio frequency (RF) magnetron sputtering from a Ni and ZnO target. A Ni seed layer was used as catalyst prior to the deposition of Ni-doped ZnO. The Ni seed layer was grown with 15 sccm of Ar flow rate while the Ni-doped ZnO was grown with mixture of Ar:O2 at 25:5 sccm gas flow rate ratio. The deposition pressure is 5 mTorr for both Ni seed layer and Ni-doped ZnO layer. This paper studies the influence of deposition temperature to the Ni seed layer and Ni-doped ZnO layer at temperature range from room temperature (RT) until 500°C with an increment of every 100°C. The sample was characterized using field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD) and UV visible spectroscopy (UV-vis) to determine the structural, crystallinity and optical properties of the deposited layer. FESEM surface analysis shows that uniformity of the nanocolumns is improved when deposition temperature is increased. The transmittance of the deposited nanocolumns was improved when temperatures are increased to 500°C.

Effects of Growth Temperature on the Structural Properties of Zinc Oxide Nanograins Deposited by RF Magnetron Sputtering

Nanograins zinc oxide (ZnO) with c-axis preferred orientation was deposited on glass substrates by RF magnetron sputtering. It was performed with a ZnO target with 99.999% purity at RF power of 200 W. The deposition was carried out in argon and oxygen ambient at the ratio flow-rates of 10 and 5 sccm respectively, with total deposition time of 1 hour. The films were grown atgrowth temperatures were specified at RT, 100, 200, 300, 400 and 500°C. The effects of the growth temperature on the ZnO structural property was investigated by x-ray diffraction (XRD). The best ZnO crystalline quality obtained at growth temperature, TG of 300°C was further characterized by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM).

Effect of Substrate Temperature on Structural and Morphological Properties of Indium Tin Oxide Nanocolumns Using RF Magnetron Sputtering

Indium tin oxide (ITO) nanocolumns were successfully deposited on both glass and silicon substrates at different substrate temperature from room temperature to 300°C by radio frequency (RF) magnetron sputtering system using an ITO target. The composition of the ITO target was 90% indium oxide and 10% tin oxide. Structures and morphological properties of ITO nanocolumns were investigated. X-ray diffraction (XRD) measurement revealed that the main preferred orientation was changed from (222) to (400) as the substrate temperature increased. The atomic force microscopy (AFM) reveals that the roughness values were increases as the substrate temperature increases. The cross sectional and top view field emission scanning electron microscopy (FESEM) images show that densely packed nanocolumn arrays were obtained from all the samples.

Effect of annealing on surface of nickel (Ni) / indium tin oxide (ITO) nanostructures measured by atomic force microscopy (AFM)

Nickel (Ni) / indium tin oxide (ITO) nanostructures were deposited on silicon (111) substrate by RF magnetron sputtering using a nickel target and metallic alloy target (In-Sn, 90%-10%). The post-deposition annealing has been done for Ni/ITO films in air and the effect of annealing temperature on the surface morphology of ITO films was studied. It has been found that the annealing temperatures increase the film surface roughness in Ni/ITO structure. At annealing temperature of 600°C, AFM analysis reveals the highest root mean square roughness, peak to valley and thickness value of 2.598 nm, 59.115 nm, and 11.358 nm, respectively. Watershed analysis on AFM images show that the numbers of grain boundaries in Ni/ITO are reduced when annealing temperature is increased to higher temperatures.

Effects of oxygen gas composition on nanocolumnar zinc oxide properties deposited by RF magnetron sputtering

Nanocolumnar ZnO was successfully deposited on glass substrate by RF magnetron sputtering. It was performed with a ZnO target with 99.999% purity at RF power of 200 W. The growth temperature was specified at 500°C, with total deposition time of 1 hour. The effects of oxygen gas composition during sputtering process was investigated. Argon to oxygen ratio was varied at Ar10:Ox5, Ar8:Ox7 and Ar5:x10 sccm. Optical characterization on samples indicated that the transmittance though visible range is higher than 80%. Based on morphological property obtained, higher oxygen content exhibited better uniformity and surface roughness. This is due to the reduction of oxygen vacancies in the ZnO layer.

Influence of substrate temperature on morphological and electrical properties of indium tin oxide nanocolumns prepared by RF magnetron sputtering

Indium tin oxide was prepared using RF magnetron sputtering at different substrate temperature. The morphological and electrical properties were investigated. Morphological properties were observed by atomic force microscopy. Electrical properties were measured using standard two-point probe measurements. The result shows that the average roughness and peak to valley value are highest at high substrate temperature. The watershed analysis shows that the total grain boundaries are highest at the substrate temperature of 200°C. The lowest resistivity value of 9.57×10-5 Ωcm is obtained from ITO nanocolumn deposited at substrate temperature of 200°C. The improvement of morphological and electrical properties as transparent conducting oxide was observed from ITO nanocolumn deposited at substrate temperature of 200°C.

Influence of RF magnetron sputtering pressure on the structural, optical, and morphological properties of indium tin oxide nanocolumns

In the present study, ITO nanocolumn was successfully deposited onto a glass substrate by RF magnetron sputtering. The effect of deposition pressure was investigated. X-ray diffraction analysis indicates that the intensity of the (400) peak orientation is highest at sputtering pressure of 5 mTorr. The results from UV-visible (UV-vis) spectroscopy revealed that the optical transmittance above 80 % was obtained from the all samples in the visible range of 400-800 nm. The larger grain size was observed from the top view of field emission scanning electron microscopy (FESEM) image as the sputtering pressure was increase. Dense nanocolumn arrays were obtained from the sample deposited at sputtering pressure of 5 mTorr. The surface roughness were decreased at high sputtering pressure of 10 mTorr was observed from atomic force microscopy (AFM) surface morphology. The electrical properties were obtained using standard two-point probe measurements. The lowest electrical resistivity was determined from the sample that prepared at sputtering pressure of 5 mTorr.