Variation of bandgap with oxygen ambient pressure in MgxZn1−xO thin films grown by pulsed laser deposition

TiO2 is a widely studied material for many important applications in areas such as environmental purification, photocatalyst, gas sensors, cancer therapy and high effect solar cell. However, investigations demonstrated that the properties and applications of titanium oxide films depend upon the nature of the crystalline phases present in the films, i.e. anatase and rutile phases. We report on the pulsed laser deposition of high quality TiO2 thin films. Pulsed Laser deposition of TiO2 thin films were performed in different ambient viz. oxygen, argon and vacuum, using a second harmonic of Nd:YAG laser of 6 ns pulse width. These deposited films of TiO2 were further annealed for 5hrs in air at different temperatures. TiO2 thin films were characterized using x-ray diffraction, SEM, photoluminescence, transmittance and reflectance. We observed effect of annealing over structural, morphological and optical properties of TiO2 thin films. The anatase phase of as-deposited TiO2 thin films is found to change into rutile phase with increased annealing temperature. Increase in crystalline behaviour of thin films with post-annealing temperature is also observed. Surface morphology of TiO2 thin films is dependent upon ambient pressure and post- annealing temperature. TiO2 thin films are found to be optically transparent with very low reflectivity hence will be suitable for antireflection coating applications.

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Radical modification of the wetting behavior of textiles coated with ZnO thin films and nanoparticles when changing the ambient pressure in the pulsed laser deposition process

Journal of Applied Physics ◽

10.1063/1.3639297 ◽

2011 ◽

Vol 110 (6) ◽

pp. 064321 ◽

Cited By ~ 24

Author(s):

A. C. Popescu ◽

L. Duta ◽

G. Dorcioman ◽

I. N. Mihailescu ◽

G. E. Stan ◽

...

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Ambient Pressure ◽

Pulsed Laser ◽

Deposition Process ◽

Laser Deposition ◽

Zno Thin Films ◽

Wetting Behavior

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Highly Conductive and Optically Transparent Polycrystalline Iridium Oxide Thin Films Grown by Reactive Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-472-373 ◽

1997 ◽

Vol 472 ◽

Cited By ~ 4

Author(s):

M.A. El Khakani ◽

M. Chaker

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Deposition Temperature ◽

Room Temperature ◽

Optical Transmission ◽

Ambient Pressure ◽

Pulsed Laser ◽

Laser Deposition ◽

Structure Morphology ◽

Quartz Substrates

ABSTRACTReactive pulsed laser deposition has been used to deposit IrO2 thin films on both SiO2 and fused quartz substrates, by ablating a metal iridium target in oxygen atmosphere. At a KrF laser intensity of about 1.7 × 109 W/cm2, IrO2 films were deposited at substrate deposition temperatures ranging from room-temperature to 700 °C under an optimum oxygen ambient pressure of 200 mTorr. The structure, morphology, electrical resistivity and optical transmission of the deposited films were characterized as a function of their deposition temperature (Td). High quality IrO2 films are obtained in the 400–600 °C deposition temperature range. They are polycrystalline with preferred orientations, depending on the substrate, and show a dense granular morphology. At a Td as low as 400 °C, highly conductive IrO2 films with room-temperature resistivities as low as (42±6) μΩ cm are obtained. Over the 300–600 °C Td range, the IrO2 films were found to exhibit a maximum optical transmission at 450 °C (∼ 45 % at 500 nm for 80 nm-thick films).

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Structural Properties and Ionic Conductivity of Ce0.8Gd0.2O2 and Ce0.8Sm0.2O2 Thin Films Grown by Pulsed Laser Deposition

3rd International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2005-74083 ◽

2005 ◽

Author(s):

Boscope M. K. Sze ◽

C. N. Wong ◽

K. H. Wong

Keyword(s):

Thin Films ◽

Ionic Conductivity ◽

Solid Oxide Fuel Cells ◽

Pulsed Laser Deposition ◽

Ambient Pressure ◽

Pulsed Laser ◽

Growth Conditions ◽

Laser Deposition ◽

X Ray Diffraction ◽

Deposited Films

Thin films of Ce0.8Gd0.2O2 and Ce0.8Sm0.2O2 oxide electrolytes have been fabricated by pulsed laser deposition on (100)LaAlO3 substrates at temperature from 300 °C to 700 °C and under 100 mTorr oxygen ambient pressure. The crystal structure, crystallinity and lattice parameters of the as-deposited films are investigated by X-ray diffraction. High quality epitaxial and polycrystalline films are obtained at different growth conditions. We have made impedance measurements on these films in the temperature range from 300 °C to 850 °C. Our results reveal a mark increase in the ionic conductivity of these films in comparison with those of the corresponding bulk materials. The observed enhancements are closely related to the crystallinity of the films. Conductivities of 0.1 S/cm or higher for Ce0.8Gd0.2O2 and Ce0.8Sm0.2O2 are obtained at 500 °C. We have demonstrated that in utilizing these thin films solid oxide fuel cells operating at below 500 °C are possible.

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Experimental Investigation of Pulsed Laser Deposition Based on a Compressible Flow Framework

Materials, Nondestructive Evaluation, and Pressure Vessels and Piping ◽

10.1115/imece2006-14219 ◽

2006 ◽

Author(s):

Biqing Sheng ◽

Zhaoyan Zhang

Keyword(s):

Thin Films ◽

Ambient Temperature ◽

Pulsed Laser Deposition ◽

Ambient Pressure ◽

Pulsed Laser ◽

Experimental Results ◽

Laser Deposition ◽

Ablation Laser ◽

Ambient Gases ◽

Film Characteristics

Pulsed laser deposition (PLD) is a popular technique for creating thin films. The film characteristics are directly related to the kinetic energy of the laser-induced plume. According to the theory of transient shock wave expansion during laser ablation, laser-induced plume properties are strongly affected by laser intensity as well as ambient temperature, pressure, and gas species. This theory leads to the development of PLD strategies to properly optimize the PLD parameters. The experiments were carried out to deposit diamond-like carbon (DLC) thin films under different ambient temperature, pressure and gas species. The deposited DLC thin films were characterized by Raman spectroscopy. Experimental results showed that the thin film quality can be improved by decreasing the ambient temperature, increasing the ambient pressure and using ambient gases with low molecular weight. Experimental results agree well with the theoretical prediction.

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INFLUENCE OF ARGON PRESSURE ON MICROSTRUCTURE AND OPTICAL PROPERTIES OF Zn0.9Se:Co0.1 THIN FILMS PREPARED BY PULSED LASER DEPOSITION

Surface Review and Letters ◽

10.1142/s0218625x18501767 ◽

2019 ◽

Vol 26 (04) ◽

pp. 1850176

Author(s):

SHU FENG LI ◽

LI WANG ◽

XUEQIONG SU ◽

DONGWEN GAO ◽

LE KONG

Keyword(s):

Thin Films ◽

Optical Properties ◽

Pulsed Laser Deposition ◽

Ambient Pressure ◽

Pulsed Laser ◽

Argon Pressure ◽

Laser Deposition ◽

Collision Probability ◽

Adsorption Effect ◽

Gas Pressures

Zn[Formula: see text]Se:Co[Formula: see text] thin films were deposited on sapphire (Al2O3) substrates in argon atmosphere at various gas pressures by pulsed laser deposition. Influence of argon pressure on the thickness, surface morphology, crystal structure and optical properties of the thin films were investigated by various diagnosis tools. It was found that these physical properties were correlated to the argon pressure and appeared like a mutation between the pressure of 2[Formula: see text]Pa and 4[Formula: see text]Pa. As the deposition pressure changed from 2[Formula: see text]Pa to 4[Formula: see text]Pa, the collision probability between ablated species and argon molecule was increased, which resulted in the transformation of the deposition type from sputter effect to adsorption effect and the mutation of film thickness and structure. These in turn influence the transmission range and band gap of the films. All of the results suggest that the ambient pressure is a very important factor to the deposition of Zn[Formula: see text]Se:Co[Formula: see text] films by PLD.

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Parametric Studies on Suppression of Secondary Phases in LiNbO3 Thin Films Deposited by Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-784-c11.24 ◽

2003 ◽

Vol 784 ◽

Author(s):

Ji-Won Son ◽

Sergei S. Orlov ◽

Bill Phillips ◽

Lambertus Hesselink

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Ambient Pressure ◽

Pulsed Laser ◽

Lattice Misfit ◽

Secondary Phase ◽

Laser Deposition ◽

Secondary Phases ◽

Mixed Films ◽

Parametric Studies

ABSTRACTWe performed a parametric study to suppress secondary phases in lithium niobate thin films by using pulsed laser deposition (PLD). A KrF excimer laser (λ=248nm) was used as a PLD source and c-oriented sapphire was used as substrates, for waveguide applications. By reducing the growth rate and changing the ambient gas pressure respectively, we found that the main parameter suppressing a secondary phase is controlling the plume strength. To investigate the relation between film phases and the plume strength, extensive parametric studies were performed by changing the oxygen ambient pressure, the target to substrate distance, and also the Li content in the target. The surface morphologies of single phase films and Li-deficient phase mixed films are compared and related to the growth mechanism with a lattice misfit. Deposition parameters to achieve lower loss films are also discussed.

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Effect of Si Layer in The ZnO Thin Films by Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-764-c3.12 ◽

2003 ◽

Vol 764 ◽

Author(s):

Hong Seong Kang ◽

Jeong Seok Kang ◽

Jae Won Kim ◽

Sang Yeol Lee

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Properties ◽

Pulsed Laser Deposition ◽

Structural Properties ◽

Ambient Pressure ◽

Pulsed Laser ◽

Laser Deposition ◽

Zno Thin Films ◽

Zno Thin Film

AbstractZnO thin films and ZnO-Si-ZnO multi-layer thin films have been deposited by pulsed laser deposition (PLD). And then, the films have been annealed at 300°C in oxygen ambient pressure. The optical and structural properties changed by Si layer in ZnO thin film. UV and visible peak position was shifted by Si layer. Electrical properties of the films were improved slightly than ZnO thin film without Si layer. The optical and structural properties of ZnO thin films and ZnOSi-ZnO multi-layer thin films were characterized by PL (Photoluminescence) and XRD(X-ray diffraction method), respectively. Electrical properties were measured by van der Pauw Hall measurements.

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