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1.
Cd1 − xZnxTe films were prepared by radio frequency (r.f.) magnetron sputtering from Cd0.9Zn0.1Te slices target with different sputtering power (60-120 W). The effects of sputtering power on the properties of Cd1 − xZnxTe films were studied using X-ray diffraction (XRD), energy dispersive X-ray (EDX), atomic force microscopy (AFM), ultraviolet spectrophotometer and Hall effect measurements. The composition of the deposited films was determined by EDX. The Cd content was found always to be higher than the Te content, regardless of sputtering power. This behavior may be explained by the preferential sputtering of cadmium atoms in the target. XRD studies suggest that ZnTe secondary phases were coexisted in Cd1 − xZnxTe films. The origin of the secondary phase is ascribed to the lowest sticking coefficient of Zn atom. AFM micrographs show that the grain size increases with the sputtering power. The optical transmission data indicate that shallow absorption edge occurs in the range of 750-850 nm, and the sputtering power does not have a clear effect on the optical absorption coefficient. In Hall Effect measurements, the sheet resistivities of the deposited films are 1.988 × 108, 8.134 × 107, 8.088 × 107 and 3.069 × 107 Ω/sq, respectively, which increase with the increasing of sputtering power. 相似文献
2.
C.C. WuD.S. Wuu P.R. LinT.N. Chen R.H. HorngS.L. Ou Y.L. TuC.C. Wei Z.C. Feng 《Thin solid films》2011,519(6):1966-1970
Wurtzite-structure MgxZn1 − xO materials with five different compositions of x from 0 to 0.14 were grown on sapphire substrates by metalorganic chemical vapor deposition. It was found that increasing Mg content in the MgxZn1 − xO not only increased the band gap energy of the film but was also beneficial to the epitaxial growth of p-type MgxZn1 − xO without using any doping sources. In addition, the combined ultraviolet photoluminescence (PL) and Raman scattering spectra were measured with PL-Raman signals obtained together, showing a blue-shift of PL band and variation of resonant Raman multi-order longitudinal optical phonon modes with an increase of Mg content. 相似文献
3.
Takahiro Itoh 《Vacuum》2007,81(9):1068-1076
The growth process of CuO and Cu2O thin films on MgO(0 0 1) substrates by reactive dc-magnetron sputtering was studied by reflection high-energy electron diffraction (RHEED) and atomic-force microscopy (AFM). The RHEED pattern and AFM image showed that (1) three-dimensional Cu(0 0 1) islands grew on MgO under the nonreactive sputtering condition, (2) CuO(1 1 1) was deposited layer by layer on MgO at 400 °C under the reactive sputtering condition, and (3) the film deposited at 600 °C in the initial growth stage was composed of three-dimensional Cu islands because O2 gas could not be incorporated into them due to the low sticking coefficient of O2 on MgO under the reactive sputtering condition. The layer-by-layer CuO(1 1 1) thin-film growth process is discussed from the viewpoint that Cu and oxygen species are supplied in stoichiometry onto the MgO substrate to form CuO thin-film crystals while maintaining minimum interfacial energy between CuO and MgO. 相似文献
4.
Transparent conducting thin films of Al-doped and Ga-doped Zn1 − xMgxO with arbitrary Mg content x were deposited on glass substrates by simultaneous RF-magnetron sputtering of doped ZnO and MgO targets, and their fundamental properties were characterized. MgO phase separation in Zn1 − xMgxO films was not detected by X-ray diffraction. The Zn1 − xMgxO films show high optical transparency in the visible region. Although the carrier density of the Zn1 − xMgxO films decreased with increasing x, the Zn1 − xMgxO films showed good electrical conductivity; electrical resistivity as low as 8 × 10− 4 Ω ·cm was achieved for the Zn0.9Mg0.1O:Ga thin film. 相似文献
5.
Flora M. Li Rob WaddinghamWilliam I. Milne Andrew J. FlewittStuart Speakman James DutsonSteve Wakeham Mike Thwaites 《Thin solid films》2011,520(4):1278-1284
With the emergence of transparent electronics, there has been considerable advancement in n-type transparent semiconducting oxide (TSO) materials, such as ZnO, InGaZnO, and InSnO. Comparatively, the availability of p-type TSO materials is more scarce and the available materials are less mature. The development of p-type semiconductors is one of the key technologies needed to push transparent electronics and systems to the next frontier, particularly for implementing p-n junctions for solar cells and p-type transistors for complementary logic/circuits applications. Cuprous oxide (Cu2O) is one of the most promising candidates for p-type TSO materials. This paper reports the deposition of Cu2O thin films without substrate heating using a high deposition rate reactive sputtering technique, called high target utilisation sputtering (HiTUS). This technique allows independent control of the remote plasma density and the ion energy, thus providing finer control of the film properties and microstructure as well as reducing film stress. The effect of deposition parameters, including oxygen flow rate, plasma power and target power, on the properties of Cu2O films are reported. It is known from previously published work that the formation of pure Cu2O film is often difficult, due to the more ready formation or co-formation of cupric oxide (CuO). From our investigation, we established two key concurrent criteria needed for attaining Cu2O thin films (as opposed to CuO or mixed phase CuO/Cu2O films). First, the oxygen flow rate must be kept low to avoid over-oxidation of Cu2O to CuO and to ensure a non-oxidised/non-poisoned metallic copper target in the reactive sputtering environment. Secondly, the energy of the sputtered copper species must be kept low as higher reaction energy tends to favour the formation of CuO. The unique design of the HiTUS system enables the provision of a high density of low energy sputtered copper radicals/ions, and when combined with a controlled amount of oxygen, can produce good quality p-type transparent Cu2O films with electrical resistivity ranging from 102 to 104 Ω-cm, hole mobility of 1-10 cm2/V-s, and optical band-gap of 2.0-2.6 eV. These material properties make this low temperature deposited HiTUS Cu2O film suitable for fabrication of p-type metal oxide thin film transistors. Furthermore, the capability to deposit Cu2O films with low film stress at low temperatures on plastic substrates renders this approach favourable for fabrication of flexible p-n junction solar cells. 相似文献
6.
Interfacial reactions and electrical properties of RF sputter deposited HfTaOx high-k gate dielectric films on Si1 − xGex (x = 19%) are investigated. X-ray photoelectron spectroscopic analyses indicate an interfacial layer containing GeOx, Hf silicate, SiOx (layer of Hf-Si-Ge-O) formation during deposition of HfTaOx. No evidence of Ta-silicate or Ta incorporation was found at the interface. The crystallization temperature of HfTaOx film is found to increase significantly after annealing beyond 500 °C (for 5 min) along with the incorporation of Ta. HfTaOx films (with 18% Ta) remain amorphous up to about 500 °C anneal. Electrical characterization of post deposition annealed (in oxygen at 600 °C) samples showed; capacitance equivalent thickness of ~ 4.3-5.7 nm, hysteresis of 0.5-0.8 V, and interface state density = 1.2-3.8 × 1012 cm− 2 eV− 1. The valence and conduction band offsets were determined from X-ray photoelectron spectroscopy spectra after careful analyses of the experimental data and removal of binding energy shift induced by differential charging phenomena occurring during X-ray photoelectron spectroscopic measurements. The valence and conduction band offsets were found to be 2.45 ± 0.05 and 2.31 ± 0.05 eV, respectively, and a band gap of 5.8 ± 05 eV was found for annealed samples. 相似文献
7.
Gel formation was realized by adding citric acid to a solution of La(NO3)3·5H2O, Ca(NO3)2·4H2O, and Fe(NO3)2·9H2O. Perovskite-type (La1−xCax)FeO3 (0 ≤ x ≤ 0.2) was synthesized by firing the gel at 500 °C in air for 1 h. The crystallite size (D1 2 1) decreased with increasing x, while the specific surface area was 6.8-9.4 m2/g and independent of x. The XPS measurement of the (La1−xCax)FeO3 surface indicated that the Ca2+ ion content increased with increasing x, while the Fe ion content was independent of x. Catalytic activity for CO oxidation increased with increasing x. 相似文献
8.
A. Khatibi J. PalisaitisC. Höglund A. ErikssonP.O.Å. Persson J. JensenJ. Birch P. EklundL. Hultman 《Thin solid films》2011,519(8):2426-2429
We report the discovery of a face-centered cubic (Al1−xCrx)2O3 solid solution [0.60 < x < 0.70] in films grown onto Si substrates using reactive radio frequency magnetron sputtering from Al and Cr targets at 400 °C. The proposed structure is NaCl-like with 33% vacancies on the metal sites. The unit cell parameter is 4.04 Å as determined by X-ray diffraction. The films have a <100> preferred crystallographic orientation and exhibit hardness values up to 26 GPa and an elastic modulus of 220-235 GPa. 相似文献
9.
Wenyong ZhangLiping Guo Guoliang PengTiecheng Li Shixuan FengZhongpo Zhou Ting PengZuci Quan 《Thin solid films》2011,520(2):769-773
Polycrystalline Si1 − xCrx thin films have been prepared by magnetron sputtering followed by rapid thermal annealing (RTA) for crystallization. RTA was performed at 800 °C for 5 min, 1200 °C for 30 s and 1200 °C for 2 min, in a N2 flow. The magnetic hysteresis loops were observed at room temperature in all the samples except for RTA at 800 °C for 5 min, and the annealing caused the decrease of saturation magnetization relative to the as-grown film. X-ray diffraction spectra and Raman spectra showed that the annealing process lead the deposited amorphous film to be crystallized and CrSi2 phase formed. The magnetism of the films was determined by the competition between crystallinity and precipitation of diamagnetic CrSi2 phase. 相似文献
10.
Zn1 − xMgxO thin films of various Mg compositions were deposited on quartz substrates using inexpensive ultrasonic spray pyrolysis technique. The influence of varying Mg composition and substrate temperature on structural, electrical and optical properties of Zn1 − xMgxO films were systematically investigated. The structural transition from hexagonal to cubic phase has been observed for Mg content greater than 70 mol%. AFM images of the Zn1 − xMgxO films (x = 0.3) deposited at optimized substrate temperature clearly reveals the formation of nanorods of hexagonal Zn1 − xMgxO. The variation of the cation-anion bond length to Mg content shows that the lattice constant of the hexagonal Zn1 − xMgxO decreases with corresponding increase in Mg content, which result in structure gradually deviating from wurtzite structure. The tuning of the band gap was obtained from 3.58 to 6.16 eV with corresponding increase in Mg content. The photoluminescence results also revealed the shift in ultraviolet peak position towards the higher energy side. 相似文献
11.
Takahiro Itoh 《Vacuum》2007,81(7):904-910
Copper oxide films deposited on MgO(0 0 1) substrates by reactive magnetron sputtering under the metal-mode condition were studied by X-ray diffraction (XRD) and reflection high-energy electron diffraction (RHEED) analyses for structural analysis, and X-ray-excited Auger electron spectroscopy (XAES) for chemical bonding analysis. CuO(1 1 1) thin films grew from their initial growth stage maintaining the same crystallinity on MgO(0 0 1) substrates at 400°C. When the substrate temperature was increased to 600 °C, the as-sputtered films comprise Cu(0 0 1), amorphous Cu2O phase, and Cu2O(0 0 1) phase. The Cu(0 0 1) phase was observed at initial growth stage. This is probably because O2 gas molecules could not sufficiently stick to the MgO substrate at 600 °C. Single phase of Cu2O(0 0 1) was obtained by the cooling of the as-sputtered films in O2 atmosphere. The growth of single phase Cu2O(0 0 1) is considered as a solid-phase heteroepitaxial growth on MgO(0 0 1) surface, which was caused by incorporating O2 gas into the as-sputtered films. 相似文献
12.
MgxZn1−xO films were deposited onto the glass substrate by a sol-gel spin coating method. The drying and annealing temperatures were 300 and 500 °C in air. As x varies from 0 to 1, it was observed that the crystal structure is changed from wurtzite ZnO to cubic MgO. The morphology characterizations of these films were observed by scanning electron microscope. The randomly oriented hexagonal nanorods were gown on the glass surface when x = 0 and 0.25, which became disappeared with increasing Mg contents. The optical properties of these films were investigated by room-temperature photoluminescence (PL) and UV-vis absorption spectra, which show that the optical band gap and photoluminescence in the visible and UV regions can be ideally tuned by varying the Mg contents in the MgxZn1−xO alloy films. 相似文献
13.
To examine variations in the transparent conducting properties after annealing at high temperatures, 300-nm thick Sb-doped Sn1 − xHfxO2 (x = 0.00-0.10) films were deposited onto silica glass substrates by the RF sputtering method and annealed in air up to 1000 °C at 200 °C increments. After annealing, all the Sb-doped SnO2 films were transparent and electrically conductive, but large cracks, which decreased the electrical conductivity, were generated in several films due to crystallization or the thermal expansion difference between the film and substrate. Only the film deposited at room temperature in an Ar and O2 mixed atmosphere did not crack after annealing, and its electrical conductivity exceeded 100 S cm− 1 even after annealing at 1000 °C in air. Hf-doping blue shifted the fundamental absorption edges in the UV region in the Sb-doped Sn1 − xHfxO2 films. Additionally, the optical transmission at 310 nm, T310, increased as the Hf concentration increased, whereas the electrical conductivity was inversely proportional to the Hf concentration. On the other hand, thinner films (150-nm thick) with x = 0.00 showed both a high electrical conductivity over 100 S cm− 1 and a high transparency T310 = 65% after high temperature annealing. 相似文献
14.
The aim of the present work is to report the study of samples with the La2 − xSr2 − xNb2O10 − x stoichiometry obtained under different synthesis conditions. The materials were characterized and studied by means of Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), X-ray diffraction analysis (XRD), and AC Susceptibility. A preliminary identification of the main peaks appearing in the diffraction patterns is shown for the synthesized phases. The La2 − xSr2 − xNb2O10 − x compound undergoes a structural change as a function sintering temperature, with three kinds of the stabilized structure, one is from 1173 < T ≤ 1373 K, another from 1423 < T ≤ 1573 K and the last one from 1623 < T ≤ 1723 K. 相似文献
15.
J. Olejní?ek C.A. KamlerS.A. Darveau C.L. ExstromL.E. Slaymaker A.R. VandeventerN.J. Ianno R.J. Soukup 《Thin solid films》2011,519(16):5329-5334
CuIn1 − xAlxSe2 (CIAS) thin films (x = 0.06, 0.18, 0.39, 0.64, 0.80 and 1) with thicknesses of approximately 1 μm were formed by the selenization of sputtered Cu―In―Al precursors and studied via X-ray diffraction, inductively coupled plasma mass spectrometry and micro-Raman spectroscopy at room temperature. Precursor films selenized at 300, 350, 400, 450, 500 and 550 °C were examined via Raman spectroscopy in the range 50-500 cm− 1 with resolution of 0.3 cm− 1. Sequential formation of InxSey, Cu2 − xSe, CuInSe2 (CIS) and CIAS phases was observed as the selenization temperature was increased. Conversion of CIS to CIAS was initiated at 500 °C. For all CuIn1 − xAlxSe2 products, the A1 phonon frequency varied nonlinearly with respect to the aluminum composition parameter x in the range 172 cm− 1 to 186 cm− 1. 相似文献
16.
The single-layered Fe100 − xPtx films of 30 nm thick with Pt contents (x) of 35-57 at.% are deposited on heated Si (100) substrate at a temperature (Ts) of 620 °C by magnetron co-sputtering. When the Pt content in the Fe-Pt alloy film is 35 at.%, the value of in-plane coercivity (Hc//) is close to perpendicular coercivity (Hc⊥) and both values are about 800 kA/m. The FePt films exhibit perpendicular magnetic anisotropy when the Pt content increases to the values of between 45 and 51 at.%. The perpendicular coercivity, saturation magnetization (Ms) and perpendicular squareness (S⊥) for Fe54Pt46 film are as high as 1113 kA/m, 0.594 Wb/m2 and 0.96, respectively. These magnetic properties reveal its significant potential as perpendicular magnetic recording media. Upon further increasing the Pt content to 57 at.%, the coercivity of the Fe-Pt film decreases drastically to below 230 kA/m and tends to be closer to in-plane magnetic anisotropy. 相似文献
17.
Thin film Bi2Sr2 − xLaxCuOy (x = 0.6) was deposited onto SrTiO3 by using DC magnetron sputtering. The structural characterization was carried by X-ray diffraction and the transport properties were carried by resistivity and Hall Effect measurements. The underdoped system near superconductor-insulator transition (SIT) was performed by partial substitution of Sr with x = 0.6 La. By varying the oxygen content in very small amounts through a vacuum anneal process, a highly precise hole-doping of thin film was obtained and the same film is changed from initial superconducting state to strongly insulating underdoped state. More than 14 doping states in the vicinity of SIT were performed and studied by electrical resistivity as function of temperature. The thermally activated behavior, log (1/T) behavior or electrical resistivity and VRH localization processes were evidenced function of doping and temperature. 相似文献
18.
CuIn1 − xAlxSe2 (CIAS) thin films were grown by a two stage process. Cu, In and Al layers were sequentially evaporated and subsequently heated with elemental selenium in a quasi-closed graphite box. Different x values (0 ≤ x ≤ 0.6) were obtained by varying the Al and In precursor layers thicknesses. Selenization conditions such as Se amount provided during the selenization process were adjusted in order to optimize the film properties. Polycrystalline CuIn1 − xAlxSe2 thin films with chalcopyrite structure were obtained. Referred to CuInSe2 thin films the lattice parameters, the (112) orientation and the average crystallite size decreased and the band gap energy increased with increasing Al content. To optimize structural properties of the CIAS films a higher Se amount was required as the x value increased. The incorporation of Al changed the thin film morphology towards smaller grain sizes and less compact structures. 相似文献
19.
An inorganic/organic vertical heterojunction diode has been demonstrated with p-type Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) deposited by spin coating on n-type Ga-doped ZnO (GZO) thin films. Transparent conducting GZO thin films are deposited on glass substrate by rf-magnetron sputtering. Electrical properties of GZO thin films are investigated depending on the processing temperatures. The resistivity, mobility and carrier concentration of the GZO thin films deposited at processing temperatures of 500 °C are measured to be about 3.6 × 10−4 Ω cm, 23.8 cm2/Vs and 7.1 × 1020 cm3, respectively. The root mean square surface roughness of the GZO thin films is calculated to be ~ 0.9 nm using atomic force microscopy. Current-voltage characteristics of the n-GZO/p-PEDOT:PSS heterojunction diode present rectifying operation. Half wave rectification is observed with the maximum output voltage of 1.85 V at 1 kHz. Low turn-on voltage of about 1.3 V is obtained and the ideality factor of the n-GZO/p-PEDOT:PSS diode is derived to be about 1.8. 相似文献
20.
Ming-Feng KuoChao-Ming Fu Chao-Yi HsuJung-Chuan Lee Yu-Hua LeeChia-Ou Chang Chan-Shin Chou 《Thin solid films》2011,519(23):8235-8238
The Al doping effects on high-frequency magneto-electric properties of Zn1 − x − yAlxCoyO (x = 0-10.65 at.%) thin films were systematically studied. In the current work, the Zn1 − x − yAlxCoyO thin films were deposited by magnetron co-sputtering onto quartz substrates. The magneto-impedance spectra of the thin films were measured by an impedance analyzer. Among all the doped films studied, the thin film with 6.03 at.% Al-doping showed the highest ac conductivity and relaxation frequency. To characterize the relaxation mechanism underlying the magneto-electric properties, a Cole-Cole impedance model was applied to analyze the impedance spectra. The analyzed result showed that the magneto-impedance of the Zn1 − x − yAlxCoyO is contributed by multiple processes of magnetization dynamics and dielectric relaxation. The results imply that Zn1 − x − yAlxCoyO may be applicable for high-frequency magneto-electric devices. 相似文献