scholarly journals Fabrication of YBa2Cu3Oy Thin Films on Textured Buffer Layers grown by Plasma Beam Assisted Deposition

1997 ◽  
Vol 50 (2) ◽  
pp. 381 ◽  
Author(s):  
M. Fukutomi ◽  
S. Kumagai ◽  
H. Maeda

A new technique named plasma beam assisted deposition (PBAD) is proposed to grow in-plane textured yttria-stabilised zirconia (YSZ) thin films on polycrystalline metallic substrates as a buffer layer for deposition of YBa2Cu3Oy (YBCO) films. The in-plane texturing of the YBCO films obtained is decisively governed by that of the YSZ buffer layer on which the YBCO grows. Because of a reduction of the weak links at high-angle grain boundaries, a marked increase in the critical current density Jc is observed with improved texturing of the YBCO films. So far, it has been demonstrated that YBCO films with Jc above 105 A cm-2 (77 K, 0 T) can be successfully deposited by a laser ablation technique. The PBAD process proposed here is found to be valuable technologically because it offers a very convenient method to grow textured films on long tape or large area substrates. An attempt was also made to grow textured films simultaneously on one side or both sides of various pieces of tape substrates. The results indicate that PBAD is one potential technique for future large scale application of YBCO films.

1994 ◽  
Vol 341 ◽  
Author(s):  
M. Lorenz ◽  
H. Hochmuth ◽  
H. Börner ◽  
D. Natusch ◽  
K. Kreher

AbstractAn arrangement for large area PLD on 3-inch wafers is proposed. In order to get a homogeneous stoichiometry and thickness distribution and small variations of superconducting properties on the 3-inch diameter, the substrate is foreseen to be rotated and additionally laterally moved up to 45 mm during deposition whereas the laser plume remains fixed.YSZ buffer layers showed thickness homogeneity of 1% within 10 mm, of 4% within 2 inch and of 8% within 3 inch diameter, respectively. For in-situ deposited YBCO thin films on r-plane sapphire with YSZ buffer layer we inductively measured within 3 inch diameter values of the critical temperature Tc(90%) from 85.9 K to 86.7 K and values of the critical current density jc(77 K) from 1 × 106 to 2 × 106 A/cm2. However, up to now the degree of epitaxy of the YBCO thin films on r-plane sapphire with YSZ buffer layer is lower compared to YBCO on MgO(100) as determined by Raman spectroscopy. Nevertheless, large area PLD seems to be a very promising technique for homogeneous coating of 3-inch wafers by epitaxial oxide thin films.


Author(s):  
Cornelia Endler-Schuck ◽  
André Weber ◽  
Ellen Ivers-Tiffée ◽  
Uwe Guntow ◽  
Johannes Ernst ◽  
...  

Gd 2 O 3 -doped ceria (GCO) is irreplaceable as interface/buffer layer between a mixed conducting cathode such as La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) and an 8 mol %Y2O3 stabilized ZrO2 (8YSZ) thin film electrolyte. To meet the demands of high performance, indispensable characteristics of this interface (LSCF/GCO/8YSZ) are (i) no reaction of GCO with LSCF or YSZ and (ii) a GCO layer that is defect-free (closed porosity, no cracks). It is well known that state-of-the-art screen printed and sintered GCO buffer layers are imperfect and ultimately reduce the overall performance. This study concentrates on the evaluation of nanoscaled GCO thin films integrated into anode supported cells (ASC). GCO thin films were deposited on 8YSZ electrolyte by a low temperature metal organic deposition (MOD) process. MOD is preferable because it is a versatile technique for large scale and low cost fabrication for various material compositions. The authors investigated the influence of preparation parameters with respect to chemical homogeneity and film quality (pores, cracks) of GCO thin films with a constant film thickness between 50 nm and 100 nm. Electrochemical performance of anode supported cells employing MOD derived GCO thin films will be presented in terms of ohmic resistance (ASRΩ) and will be evaluated in contrast to screen printed and sintered GCO thick films. Nanoscale MOD derived thin films with low processing temperatures and dense film qualities were vastly superior to state-of-the-art GCO and beneficial to the overall cell performance.


2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.


1992 ◽  
Vol 275 ◽  
Author(s):  
G. Cui ◽  
C. P. Beetz ◽  
B. A. Lincoln ◽  
P. S. Kirlin

ABSTRACTThe deposition of in-situ YBa2CU3O7-δ Superconducting films on polycrystalline diamond thin films has been demonstrated for the first time. Three different composite buffer layer systems have been explored for this purpose: (1) Diamond/Zr/YSZ/YBCO, (2) Diamond/Si3N4/YSZ/YBCO, and (3) Diamond/SiO2/YSZ/YBCO. The Zr was deposited by dc sputtering on the diamond films at 450 to 820 °C. The YSZ was deposited by reactive on-axis rf sputtering at 680 to 750 °C. The Si3N4 and SiO2 were also deposited by on-axis rf sputtering at 400 to 700 °C. YBCO films were grown on the buffer layers by off-axis rf sputtering at substrate temperatures between 690 °C and 750 °C. In all cases, the as-deposited YBCO films were superconducting above 77 K. This demonstration enables the fabrication of low heat capacity, fast response time bolometric IR detectors and paves the way for the use of HTSC on diamond for interconnect layers in multichip modules.


2013 ◽  
Vol 774-776 ◽  
pp. 954-959
Author(s):  
Xiao Jing Wang

The electrical properties need to be improved, although Aluminum doped ZnO thin films (ZnO: Al) have been successfully deposited on transparent TPT substrates by our group. In this paper, ZnO: Al film was deposited on TPT substrate with SiO2 buffer layer by RF magnetron sputtering. The obtained film had a hexagonal structure and highly (002) preferred orientation. Compared with ZAO film without buffer layer, the lattice constant distortion of the film with buffer layer was decreased and the compressive stress was decreased by 9.2%, reaching to 0.779GPa. The carrier concentration and hall mobility of the film with buffer layer were both increased; especially the carrier concentration was enhanced by two orders of magnitude, reaching to 2.65×10+20/cm3. The resistivity of ZAO film with SiO2 buffer layer was about 7.6×10-3 Ω·cm and the average transmittance was over 70% in the range of 450~900nm.


2005 ◽  
Vol 15 (2) ◽  
pp. 2699-2702 ◽  
Author(s):  
M. Sohma ◽  
I. Yamaguchi ◽  
K. Tsukada ◽  
W. Kondo ◽  
K. Kamiya ◽  
...  
Keyword(s):  

2020 ◽  
Vol 20 (11) ◽  
pp. 6659-6664
Author(s):  
Jeong Eun Park ◽  
So Mang Park ◽  
Eun Ji Bae ◽  
Donggun Lim

Zinc Sulfide (ZnS) is an environmentally friendly material with a wide bandgap (Eg = 3.7 eV) comparable to that of cadmium sulfide (CdS) (2.4 eV), which is conventionally used as buffer layer in Cu(In,Ga)Se2 (CIGS) thin film solar cells. Conventional ZnS buffer layers are manufactured using thiourea, and, these layers possess a disadvantage in that their deposition rate is lower than that of CdS buffer layers. In this paper, thioacetamide (TAA) was used as a sulfur precursor instead of thiourea to increase the deposition rate. However, the ZnS thin films deposited with TAA exhibited a higher roughness than the ZnS thin films deposited with thiourea. Sodium citrate was therefore added to increase the uniformity and decrease the roughness of the former ZnS thin films. When sodium citrate was used, the thin films demonstrated a high transmittance via the controlled generation of particles. In the case of TAA–ZnS thin films doped with a sodium citrate concentration of 0.04 M, the granules on the surface disappeared and these thin films were denser than the TAA–ZnS thin films deposited with a lower sodium citrate concentration. It is considered that the rate of the ion-by-ion reaction increased due to the addition of sodium citrate, thereby resulting in a uniform thin film. Consequently, TAA–ZnS thin films with thicknesses of approximately 40 nm and high transmittances of 83% were obtained when a sodium citrate concentration of 0.04 M was used.


1997 ◽  
Vol 12 (4) ◽  
pp. 1152-1159 ◽  
Author(s):  
Sangsub Kim ◽  
Shunichi Hishita

We report the results of a study on the deposition and characterization of partially oriented BaTiO3 thin films on MgO-buffered Si(100) by radio-frequency magnetron sputtering. The structural and morphological characteristics of the MgO buffer layer were investigated as a function of substrate temperature. The x-ray θ-2θ, φ scans, and observation of surface morphology revealed that MgO grew with a tendency of (001) orientation. Partially (00l) or (h00) textured BaTiO3 thin films were obtained on Si(100) with the MgO buffer layer while randomly oriented BaTiO3 thin films with large-scale cracks on the surface were made without the MgO layer. Pt/BaTiO3/Pt multistructures were formed on Si(100), MgO/Si(100), and MgO(100) single crystal substrates to conduct preliminary electrical measurements for metal-insulator-metal type capacitor. Comparison of the crystallographic orientation, morphology, and electrical properties between the BaTiO3 films on Si(100) with and without the MgO buffer layer supported the favorable role of the MgO layer as a buffer for the growth of BaTiO3 films on Si(100).


1995 ◽  
Vol 10 (5) ◽  
pp. 1086-1090 ◽  
Author(s):  
J.H. Kroese ◽  
A.J. Drehrman ◽  
J.A. Horrigan

Thin films of Y-stabilized ZrO2 (YSZ) were deposited by RF diode sputtering on R-plane sapphire as a buffer layer for the deposition of YBa2Cu3O3 (YBCO). By increasing the partial pressure of oxygen in the sputter gas mixture from 20% to 50%, it was found that the substrate temperature required to obtain (100) oriented YSZ deposition could be lowered to 630 °C from 800 °C. This change is attributed to heating or mixing effects at the film surface, due to an increase in negative ion bombardment, which supplements the effects of external heating. Increases in the partial pressure of oxygen beyond 50% were found to be counterproductive. YBCO films, deposited on the YSZ buffer layers via magnetron sputtering, showed c-axis orientation and transition temperatures of 82 K. Orientation of both the YSZ and YBCO films was confirmed by x-ray diffraction and SEM characterization.


2005 ◽  
Vol 20 (6) ◽  
pp. 1529-1535 ◽  
Author(s):  
Ai Kamitani ◽  
S. Adachi ◽  
H. Wakana ◽  
K. Tanabe

Y0.9Ba1.9La0.2Cu3Oy (La-YBCO) thin films were prepared by an off-axis magnetron sputtering method on MgO substrates with and without a BaZrO3 buffer layer. Insertion of BaZrO3 buffer layer was effective for obtaining La-YBCO films with pure c-axis orientation and in-plane alignment at low temperatures below 600 °C. We prepared La-YBCO thin films on BaZrO3-buffered MgO substrates using a temperature-gradient method, in which a template La-YBCO layer was first deposited at 600 °C, and then the temperature was continuously raised to 700 °C. By this method, La-YBCO thin films with improved crystallinity were successfully prepared. It was also proved that the insertion of the BaZrO3 buffer layer enables us to prepare high-quality La-YBCO films with high reproducibility.


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