Rf-Magnetron Sputtering Research Papers - Academia.edu (original) (raw)

In particular, the dye-sensitised solar cells (DSSCs) have a high potential in the rational energy conversion efficiency to secure our sustainable energy source. In the present study, advanced radio frequency (RF) magnetron sputtering... more

In particular, the dye-sensitised solar cells
(DSSCs) have a high potential in the rational energy conversion
efficiency to secure our sustainable energy source.
In the present study, advanced radio frequency (RF) magnetron
sputtering technique was applied to incorporate
titanium dioxide (TiO2) dopants into reduced graphene
oxide (rGO) nanosheet for improving the power conversion
efficiency (PCE) of DSSCs device. An optimum TiO2
content incorporated onto rGO nanosheet plays an important
role in improving the PCE of DSSCs by minimising
the recombination losses of photo-induced charge carriers.
Based on the results obtained, 40-s sputtering duration for
incorporating TiO2 dopants onto rGO nanosheet exhibits a
maximum PCE of 8.78% than that of pure rGO film
(0.68%). In fact, the presence of optimum content of TiO2
dopants within rGO nanosheet could act as mediators for
efficient separation photo-induced charge carriers. However,
the excessive of sputtering duration (e.g. 60 s) of
TiO2 dopants onto rGO nanosheet results higher charge
recombination and lowers the PCE of DSSCs (5.39%).

Undoped and 2% Ga-doped ZnO films have been deposited by RF magnetron sputtering onto single crystal Si (1 0 0) substrates equivalent to the commercial Si solar cells. The same films were also grown on amorphous silica substrates to... more

Undoped and 2% Ga-doped ZnO films have been deposited by RF magnetron sputtering onto single crystal Si (1 0 0) substrates equivalent to the commercial Si solar cells. The same films were also grown on amorphous silica substrates to complete their characterization. The films have been characterized by X-ray diffraction, electrical and optical measurements, X-ray photoelectron spectroscopy, Raman microspectroscopy and scanning and high-resolution transmission electron microscopy. Films present a very good quality crystalline wurtzite structure with the c-axis perpendicular to the substrate, with continuity of the (0 0 0 2) planes along the whole film, as shown by transmission electron microscopy. The doped sample shows an increase of two orders of magnitude of the electrical conductivity, an optical transmittance bigger than 85% along the visible spectrum, a diminution of the grain size in the direction parallel to the substrate and a lower surface roughness. The Ga-cations act only as substitutional impurities, they are homogeneously distributed in the whole film, maintaining the wurtzite structure and increasing the carrier density. The formation of any spurious phase or segregation of Ga2O3 clusters that can act as carrier traps can be discarded. The characterization results allow us to conclude that the doped film has improved electrical and optical properties with respect to the undoped one. Therefore, the Ga-doped films are very suitable candidates as transparent conducting electrodes for solar cells, displays and other photoelectronic devices.High-resolution image of the interface between silicon substrate and the high-quality ZnO film. ► High quality ZnO and Ga:ZnO (2%at) films prepared by magnetron sputtering on Si (100) substrates. ► Both films show a continuity of the (0002) planes along the whole film. ► Ga cations act only as substitutional impurities, homogeneously distributed in the entire film. ► Ga-doping improves the electrical and optical properties of ZnO film.

Multicomponent amorphous oxides are starting to emerge as a class of appealing semiconductor materials for application in transparent electronics. In this work, a high performance bottom-gate n-type transparent thin-film transistors are... more

Multicomponent amorphous oxides are starting to emerge as a class of appealing semiconductor materials for application in transparent electronics. In this work, a high performance bottom-gate n-type transparent thin-film transistors are reported, being the discussion primarily focused on the influence of the indium zinc oxide active layer thickness on the properties of the devices. For this purpose, transparent transistors with active layer thicknesses ranging from 15 nm to 60 nm were produced at room temperature using rf magnetron sputtering. Optical transmittance data in the visible range reveals average transmittance higher than 80%, including the glass substrate. The devices work in the enhancement mode and exhibit excellent saturation drain currents. On–off ratios above 107 are achieved, but this value tends to be lower for devices with thicker semiconductor films, as a result of the decrease in the resistance of the channel region with increasing thickness. Channel mobilities are also quite respectable, with some devices presenting values around 40 cm2/V s, even without any annealing or other post-deposition improvement processes. Concerning the evolution of threshold voltage with the thickness, this work shows that it increases from about 3 V in thicker films up to about 10 V in the thinnest ones. The interesting electrical properties obtained and the versatility arising from the fact that it is possible to modify them changing only the thickness of the semiconductor makes this new transparent transistors quite promising for future transparent ICs.

— We present the effect of hydrogen on surface characterization by Rf magnetron sputtered ZnO:Al thin films. ZnO:Al films are self textured and surface roughness of ZnO:Al films varies with H 2 dilution ratio and ultimately affects on... more

— We present the effect of hydrogen on surface characterization by Rf magnetron sputtered ZnO:Al thin films. ZnO:Al films are self textured and surface roughness of ZnO:Al films varies with H 2 dilution ratio and ultimately affects on diffused transmittance varies from 41-27% with the variation of hydrogen (5-40%) with improved resistivity of 3.9×10-4 Ω-cm. The light scattering effect of hydrogen textured thin films was evaluated by the measurement of diffused transmittance. Experimental result shows that introduction of hydrogen effect significantly improved the light trapping in terms of diffuse transmittance without affecting electrical and other optical properties of ZnO:Al thin film.

Ni–Al thin films were deposited on Ni- and Fe-based superalloys by RF magnetron sputtering in this work. The microstructures of the as-deposited films were characterized by XRD, AFM, and FE-SEM/EDS. The grain size of the Ni–Al thin films,... more

Ni–Al thin films were deposited on Ni- and Fe-based superalloys by RF magnetron sputtering in this work. The microstructures of the as-deposited films were characterized by XRD, AFM, and FE-SEM/EDS. The grain size of the Ni–Al thin films, using XRD results, was found to be 8.1 nm, 9.22 nm and 16.04 nm for Superni 76 (SN 76), Superni 750 (SN 750) and Superfer 800 (SF 800), respectively. The surface roughness of NiAl coated superalloys was calculated by using its AFM images and it showed a regular smooth surface. The Ni–Al thin films deposited superalloys were subjected to oxidation studies at 900 °C for 100 cycles. The kinetics of oxidation was determined from the weight change of the samples monitored under cyclic conditions. The oxide scales formed on the bare and Ni–Al deposited superalloys were characterized to elucidate the mechanisms of high temperature oxidation. The SF 800 superalloy has provided a better oxidation resistance in the given environment compared to SN 76 and SN 750 alloy. The weight gain was high in case of Ni–Al coated SN 750 but it was less on the coated SF 800 alloy, indicating a better protection among the coated superalloys.

Thin films of bioactive glass-ceramics have been deposited on titanium and silicon substrates by RF magnetron sputtering. The crystalline phases and the microstructure of the films have been characterized using XRD and SEM analysis; the... more

Thin films of bioactive glass-ceramics have been deposited on titanium and silicon substrates by RF magnetron sputtering. The crystalline phases and the microstructure of the films have been characterized using XRD and SEM analysis; the main phases present were calcium–magnesium phosphates, enstatite and forsterite. The adhesion of the films on titanium has been examined by pull-off testing; the adhesion strength for as-deposited films was around 40 MPa, but after crystallization the strength dropped to about half this value due to the presence of cracks. Samples kept in simulated body fluid showed an apatite-like layer, suggesting that the films are bioactive.

Columnar-structured rutile TiO2 film with a thickness of 1.4μm is prepared using the radio-frequency (RF) magnetron sputtering technique, for application in dye-sensitized solar cells (DSSCs). Pure rutile TiO2 films are fabricated by... more

Columnar-structured rutile TiO2 film with a thickness of 1.4μm is prepared using the radio-frequency (RF) magnetron sputtering technique, for application in dye-sensitized solar cells (DSSCs). Pure rutile TiO2 films are fabricated by controlling the substrate temperature during sputtering and using a substrate with a rough surface morphology. Successive substrate heating to 623K induces the growth of a rutile TiO2 film