Single Ceramic Target Research Articles

Structural and optical investigations on direct current (DC) magnetron sputtered CZTS thin film

Cu2ZnSnS4 has been grown by using DC sputtering onto the soda-lime glass (SLG). A single ceramic target has been used to deposit thin films. The deposition has been carried out at various substrate temperatures from room temperature to 400 ℃ at constant 50 W DC sputtering power. The structural and optical measurements were performed using the x-ray diffractometer and UV–Vis-NIR spectrophotometer. The study reveals the dependence of the preferred orientation of crystal on the substrate temperature. At room temperature, the CZTS thin films show amorphous crystalline nature. While crystallinity has been improved with an increase in temperature. CZTS thin films deposited at 400 ℃ show a highly crystalline structure with preferred orientation to the (112) plane. Optical investigation demonstrates a decrease in band gap upon the increase in substrate temperature. Urbach energy and crystallite size show good agreement.

Preparation of Cu3SnS4 film with single ceramic target magnetron sputtering for Pt-free counter electrode of dye-sensitized solar cell

Preparation of Cu3SnS4 film with single ceramic target magnetron sputtering for Pt-free counter electrode of dye-sensitized solar cell

The Effect of RF Sputtering Conditions on the Physical Characteristics of Deposited GeGaN Thin Film

Ge0.07GaN films were successfully made on Si (100), SiO2/Si (100) substrates by a radio frequency reactive sputtering technique at various deposition conditions listed as a range of 100–400 °C and 90–150 W with a single ceramic target containing 7 at % dopant Ge. The results showed that different RF sputtering power and heating temperature conditions affected the structural, electrical and optical properties of the sputtered Ge0.07GaN films. The as-deposited Ge0.07GaN films had an structural polycrystalline. The GeGaN films had a distorted structure under different growth conditions. The deposited-150 W Ge0.07GaN film exhibited the lowest photoenergy of 2.96 eV, the highest electron concentration of 5.50 × 1019 cm−3, a carrier conductivity of 35.2 S∙cm−1 and mobility of 4 cm2·V−1∙s−1.

Metal oxide composite thin films made by magnetron sputtering for bactericidal application

Abstract To broaden the application of antibacterial catalysts, ZnO/Ag2O composite thin films with different Ag2O contents have been successfully synthesized on non-woven fabric at room temperature by radio frequency (RF) sputtering with a single ceramic target formed by hot pressing ZnO/Ag2O nanocomposite powder in Ar atmosphere at 180 °C for 30 min. The composite thin films were also sputtered on glass substrates for characterizations. The best sputtering condition was found with the Ar/O2 gas flow ratio at 7:1 to obtain pure Ag2O thin film. The deposition of Ag2O nanoparticles on commercially available ZnO particles was also confirmed by HR-TEM prior to hot pressing for synthesizing ceramic targets. In this work, an appropriate amount of Ag2O incorporated in the composite film was endeavored by forming p–n junction to lower the cost without decreasing bactericidal ability of composite film. The amount of 45 wt% Ag2O in composite thin film to provide bactericidal effect was found to be as good as pure Ag2O. The feasibility in bactericide is due to the light sensitization of low bandgap Ag2O and the formation of nano p–n heterojunction between p-type Ag2O and n-type ZnO for efficient photo carrier separation. The dependence of antibacterial effect of ZnO/Ag2O thin films on the Ag2O content is demonstrated and elucidated in this work.

Cu2ZnSnSb(S,Se,Te)4 film formation from selenization of sputtered self-prepared single ceramic target

Single-layered Cu2ZnSnSb(S,Se,Te)4(CZTASSeTe) thin films were prepared on Mo/glass substrate by radio frequency magnetron sputtering of a self-prepared single ceramic target. Successive selenization for the as-deposited film at a substrate temperature of 200°C in Se-atmosphere was performed at various temperatures between 400°C and 600°C for 1h. Structural investigation of the grown films revealed single-phase tetragonal structure corresponding to kesterite CZTSSe. All measured samples were found to exhibit p-type conductivity. An improved grain size and crystal quality with suitable atomic ratio [Cu/(Zn+Sb+Sn)=0.89, Zn/Sn=1.15, and metal/(S+Se+Te)=1.02] obtained for CZTASSeTe film selenized at 600°C. The Hall concentration increased from 1.06 to 5.8×1017cm−3, mobility increased from 2.82 to 44.3cm2V−1s−1, and resistivity decreased from 20.92 to 0.24Ωcm as the precursor film is selenized to 600°C. An enhanced Hall mobility can be ascribed to the larger grains with better crystallinity and composition in the selenized film at 600°C. Our large grain size and maximized mobility for CZTASSeTe film at the selenization temperature of 600°C from single ceramic target can be useful for the fabrication of the CZTASSeTe absorber layer.

Long-throw magnetron sputtering of amorphous Zn-Sn-O thin films at room temperature

We report on the fabrication of amorphous zinc tin oxide (ZTO) thin films by long-throw magnetron sputtering on glass substrate. This method is especially appropriate for the growth of amorphous oxides at room temperature. ZTO films were deposited from single ceramic target and via co-sputtering of ZnO and SnO targets in inert Ar atmosphere only. Without additional annealing steps, the films showed a minimum resistivity of m and a maximum resistivity of m. The conductivity can be tuned via total pressure, power ratio in case of co-sputtering and the applied substrate voltage from semiconducting to insulating. Furthermore, 30 nm thick ZTO films deposited at room temperature showed a mean transmittance of 90% in the visible spectral range, are X-ray amorphous, and their surface roughness is as low as nm. The application of these films is shown in the demonstration of an all amorphous oxide pn-diode.

Morphological evolution and structural properties of Cu2ZnSn(S,Se)4 thin films deposited from single ceramic target by a one-step sputtering process and selenization without H2Se

Cu2ZnSn(SSe)4 (CZTSSe) thin films were successfully deposited on TiN/Mo-coated glass substrate using RF-sputtering from single ceramic CZTSSe target, followed by annealing at 400–600°C for 1h in Se atmosphere. The influence of substrate heating (RT−300°C) and post-selenization on the morphological, structural, and compositional properties of the films were investigated using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy, as well as by Raman scattering and X-ray photoelectron spectroscopy. The crystallinity with preferential (112) orientation of the as-sputtered precursor films increased with increasing the substrate temperature and the selenization temperature. Compared with the thin films as deposited, post-selenization (400–600°C) further improved the microstructure features and elemental compositions. The thin films selenized at 600°C got dense microstructure and large grain size of 2μm, nearly stoichiometric Cu-poor and Zn-rich compositions with Cu/(Zn+Sn+Sb) ∼0.78 and Zn/Sn ∼1.24, and tetragonal structure with lattice parameters a=5.663Å, c=11.234Å. This study provides an insight into the use of single ceramic CZTSSe target sputtering method to demonstrate the selenization conditions, such as substrate temperature and selenium partial pressure, for improving the film crystallinity, stoichiometry and grain growth.

Properties of ITO films deposited by RF superimposed DC magnetron sputtering

ITO films were deposited using a RF superimposed DC magnetron sputtering system with an ITO (90.0 wt% In 2O 3 and 10.0 wt% SnO 2) single ceramic target at either room temperature or the crystallization temperature of ITO films (170 °C). The total sputtering power (DC + RF) was maintained at 70 W, and the RF portion of the total power was varied from 0% to 100%. The discharge voltage and deposition rate decreased with increasing RF portion of the total power. The (2 2 2) X-ray diffraction peak showed the highest intensity at a RF/(RF + DC) power ratio of 50% with a total power of 70 W. The ITO film deposited at a RF/(RF + DC) power ratio of 50% at 170 °C showed relatively low resistivity (2.52 × 10 −4 Ω cm).

Three-dimensional heteroepitaxy in self-assembled BaTiO3–CoFe2O4 nanostructures

Self-assembled BaTiO3–CoFe2O4 complex oxide nanostructures have been synthesized by pulsed laser deposition. A single ceramic target with a molar ratio of 0.62BaTiO3–0.38CoFe2O4 was used. Spinel CoFe2O4 and perovskite BaTiO3 phases spontaneously separated during heteroepitaxial growth on a single-crystal SrTiO3(001) substrate. The nanostructures are epitaxial in-plane as well as out-of-plane, with CoFe2O4 nanopillar arrays embedded in a BaTiO3 matrix. The CoFe2O4 nanopillars have uniform size and spacing and nearly circular cross section. As the substrate temperature increases from 750 to 950°C, the average diameter of the pillars increases from ∼9 to ∼70nm.

Epitaxial Y-Ba-Cu-O thin films on MgO deposited by high-pressure reactive magnetron sputtering

Y-Ba-Cu-O thin films have been prepared on MgO(100) substrates by rf reactive magnetron sputtering from a single ceramic target. By adopting high total pressures, typically 280 mTorr, and relatively low substrate temperatures of approximately 650 °C, epitaxial films with the relations (001) YBa2Cu3Oy∥(001)MgO and [100]YBa2Cu3Oy∥[100]MgO can be reproducibly obtained. A high degree of epitaxy is confirmed by x-ray pole figure measurements and ion channeling. These films require a brief rapid thermal oxygen anneal at typically 850 °C, to exhibit sharp superconducting transitions with zero resistance around 75 K. Films deposited at higher temperatures above 700 °C show transitions as deposited with zero resistance near 80 K. The quality of the transition is correlated with expanded lattice constants with the best transitions occurring in films whose lattice constants approach that of the bulk. The films have high critical current densities of 1–5×106 A/cm2 at 4.2 K. They also show good uniformity and excellent surface morphology with a roughness less than 10 nm and can be readily patterned to micrometer and submicrometer dimensions.