- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Improved Photovoltaic Effect of <i>pa??ia??n</i> Structured BiFeO <sub/>3</sub> Film Deposited by Radio-Frequency Magnetron Sputtering
摘要： Pure phase polycrystalline BiFeO3 ?lm was deposited onto FTO substrate by RF magnetron sputtering method. SEM result shows that BiFeO3 ?lm has the obvious porosity and large clusters which lead to the poor ferroelectric and photovoltaic properties in FTO/BiFeO3/Ag device. However, these properties are improved in p–i–n structured FTO/TiO2/BiFeO3/HTM/Ag device by incorporating the electron and hole transport materials. The hysteresis loop measurement demonstrates the excellent ferroelectric property with large remnant polarization (2Pr = 180 (cid:2)C/cm2) and low leakage current. The J–V curve shows the short-circuit current density is dozens of times larger than that of FTO/BiFeO3/Ag device. Moreover, the photovoltaic output depends on the poling ?eld where the positive poling improves the short-circuit current density to ?85 (cid:2)A/cm2 and the negative poling reduces both the photocurrent and photovoltage. It is believed that the ferroelectric polarization plays a dominant role in the photovoltaic effect.
关键词： BiFeO3 Film,Sputtering,Photovoltaic Effect
更新于2025-09-23 15:19:57
-
Characterization of sputtered MoOx thin films with different oxygen content and their application as back contact in CdTe solar cells
摘要： Transparent MoOx thin films with varied composition were successfully prepared by sputtering and the effects of oxygen contents on the composition stoichiometry, defect states, work functions, electrical and optical properties of MoOx films were systematically studied. These thin films were then utilized in cadmium telluride solar cells to act as back contact buffers. As compared with the CdTe solar cells with Au back contact, deteriorated performance was witnessed in those with MoOx buffers. The deterioration was demonstrated to be caused by the oxidation of CdTe surface, the large valence band offset and the insufficient work function. Finally, by optimizing the back contacts to form a CuCl/MoOx/ITO composite back contact, the efficiency was improved to 11.8%. This work demonstrates feasible approaches to prepare MoOx thin films with varied oxygen concentrations which could be easily applied to many other thin film solar cells and provide important indications in the preparation and optimization of the performance for bifacial devices.
关键词： Back contact,CdTe solar Cells,Molybdenum oxide,Magnetron sputtering
更新于2025-09-23 15:19:57
-
Optical properties of ZnO thin films deposed by RF magnetron
摘要： We have grown ZnO thin films on glass substrate by RF magnetron sputtering using metallic zinc target. The influences of some parameters on thin film optical properties were assessed. They exhibited extremely high resistivity of 1012 ?.cm, an energy gap of 3.3 eV at room temperature. It was found that a RF power of 50 W, a target to substrate distance of 70 mm, very low gas pressures of 3.35 x 10-3 Torr of argon and oxygen mixed gas atmosphere gave ZnO thin films with a good homogeneity and a high crystallinity. All the films are transparent in the visible region (400 to 800 nm) with average transmittance above 80%. The optical transmittance and refractive index, calculated from the spectra of optical absorbance, show a significant dependence on the growth parameters. As for the sample grown at 100°C, the average transmittance is about 80% in the visible wavelength range and the refractive index is estimated to be 1.97.
关键词： X-ray diffraction,RF sputtering magnetron,refractive index,ZnO,transmittance
更新于2025-09-23 15:19:57
-
Electrical characterization of two analogous Schottky contacts produced from <i>N</i> -substituted 1,8-naphthalimide
摘要： The aim of this study was to analyze the interface states (Nss) in pure Al//p-Si/Al, Al/N-F Nft/p-Si/Al and Al/N-T Nft/p-Si/Al Schottky barrier diodes (SBDs). N-Substituted 1,8-naphthalimide thin films were deposited on a p-Si substrate by spin coating and annealed at B200 1C for 60 s under an air atmosphere. Al contacts were obtained via reactive magnetron sputtering. The current voltage (I–V) characteristics of the SBDs were measured at room temperature. From the I–V characteristics, the SBDs ideality factor (n) and zero-bias barrier height values (Fb) of 1.27, 1.00, and 1.05 and 0.66 eV, 0.70 eV, and 0.64 eV were observed for the Al//p-Si/Al, Al/N-F Nft/p-Si/Al and Al/N-T Nft/p-Si/Al Schottky barrier diodes, respectively. The interface state density distribution profile (Nss) as a function of (Ess–Ev) was extracted from the forward-bias I–V measurements by considering the effective barrier height and (Fe) and series resistance (Rs) of the Schottky diode. The obtained Nss plot tendency showed that the existence of interface states has no significant effect on the rectifying and capacitance characteristics. The Nss values with the 1,8-naphthalimide layer were lower than that without it. This shows that naphthalimide exhibits a strong contribution by blocking the unwanted states and some traps in the conduction mechanism, which may cause possible cracks or deep paths for carriers to travel along the junction.
关键词： magnetron sputtering,interface states,Schottky barrier diodes,spin coating,1,8-naphthalimide
更新于2025-09-23 15:19:57
-
Structural transformation identification of sputtered amorphous MoS <sub/>x</sub> as efficient hydrogen evolving catalyst during electrochemical activation
摘要： Molybdenum sulfide MoSx is considered as attractive hydrogen evolution catalyst since it is free of noble metals and shows a low overpotential. Especially, amorphous molybdenum sulfide has attracted attention because of its high catalytic activity. However, the catalytic mechanism of the hydrogen evolution reaction is not yet fully understood. Therefore in our study, layers of MoSx were deposited by reactive magnetron sputtering varying the substrate temperature in the range from room temperature (RT) to 500°C. The morphology and structure of the films change significantly as a function of temperature, from an amorphous to a highly textured 2H-MoS2 phase. The highest catalytic activity was found for amorphous layers deposited at RT showing an overvoltage of 180 mV at a current density of -10 mAcm-2 in a 0.5 M sulfuric acid electrolyte (pH 0.3) after electrochemical activation. As detected by Raman spectroscopy the RT deposited catalyst consists of [Mo3S13]2- and [Mo3S12]2- entities which are interconnected via [S2]2- and S2- ligands. When sweeping the potential from 0.2 to -0.3 V vs RHE a massive release of sulfur in form of gaseous H2S was observed in the first minutes as detected by differential electrochemical mass spectroscopy (DEMS). After electrochemical cycling for 10 min, the chains of these clusters transform into a layer-type MoS2-x phase observed by in-situ Raman spectroscopy. In this transformation process, H2S formation gradually vanishes and H2 evolution becomes dominant. The transformed phase is considered as a sulfur deficient molybdenum sulfide characterized by a high number of molybdenum atoms located at the edges of nano-sized MoSx islands, which act as catalytically active centers.
关键词： hydrogen evolving catalyst,structural transformation,water splitting,molybdenum sulfide,sputtering
更新于2025-09-19 17:15:36
-
Cu <sub/>2</sub> O porous nanostructured films fabricated by positive bias sputtering deposition
摘要： In this work, the authors fabricated Cu2O porous nanostructured films (PNFs) on glass slide substrates by the newly developed positive bias deposition approach in a balanced magnetron sputtering (MS) system. It was found that the surface morphology, crystal structure and optical property of the as-deposited products were greatly dependent on the applied positive substrate bias. In particular, when the substrate was biased at +50 and +150 V, both of the as-prepared Cu2O PNFs exhibited a unique triangular pyramids-like structure with obvious edges and corners and little gluing, a preferred orientation of (111) and a blue shift of energy band gap at 2.35 eV. Quantitative calculation results indicated that the traditional bombardment effects of electrons and sputtering argon ions were both negligible during the bias deposition in the balanced MS system. Instead, a new model of tip charging effect was further proposed to account for the controllable formation of PNFs by the balanced bias sputtering deposition.
关键词： positive bias deposition,balanced magnetron sputtering,Cu2O,porous nanostructured films
更新于2025-09-19 17:15:36
-
Optical, electrical and microstructural properties of SiC thin films deposited by reactive dc magnetron sputtering
摘要： In this study, amorphous silicon carbide (SiC) thin films of variable compositions were deposited on Si (100) and glass substrates by reactive direct current magnetron sputtering of high purity silicon target, using CH4 as reactive gas. The composition and the properties of the coatings have been modified by the change in the reactive gas flow rate from 5% to 50%. Spectrophotometer has been used to measure the optical transmittance and reflectance of silicon carbide thin films over the spectral range from 280 to 1000 nm. The optical constants such as refractive indices and the extinction coefficients of the films were calculated. The band gap values of the deposited films were further evaluated with respect to the gas flow rate. Transmittance values of SiC films changed from 85% to almost 0% in the visible light range. The optical band gap values of the films were altered from 1.7 to 2.7 eV. The activation energy was found to increase from 0.16 eV up to 1 eV and dark conductivity decreased from 7.42x10-4 to 1.06x10-9 Ω-1cm-1 while carbon concentration in the films increased. The results demonstrated that the optical and electrical properties of SiC films could easily be tailored by modifying Si and C concentrations in the coating composition, for the same film thicknesses.
关键词： optical properties,microstructural properties,Silicon carbide thin films,electrical properties,reactive direct current magnetron sputtering
更新于2025-09-19 17:15:36
-
Growth of Cu<sub>2</sub>ZnSnS<sub>4</sub> (CZTS) thin films using short sulfurization periods
摘要： In this study CZTS thin films were grown by a two-stage process that involved sequential sputter deposition of metallic Cu, Zn, and Sn layers on Mo coated glass substrates followed by RTP annealing at 530 and 560 °C for various dwell times (1, 60, and 180 sec). CZTS thin films obtained by reaction at different sulfurization temperatures and reaction times were characterized employing XRD, Raman spectroscopy, SEM, EDX, and photoluminescence. It showed that extension of the sulfurization time provides better crystalline quality except for the CZTS560-60 thin film. SEM surface microstructure of the films displayed non-uniform, dense, and polycrystalline structure. The optical band gap of the films as determined by photoluminescence was found to be about 1.36-1.38 eV. It was observed that it is possible to obtain Cu-poor and Zn-rich CZTS thin films with short dwell time of reactions. XRD pattern and Raman spectra of the films showed formation of kesterite CZTS structure and some secondary phases such as CuS, SnS, SnS2. The full-width-at-half-maximum (FWHM) values extracted from the (112) diffraction peaks of the CZTS thin films.
关键词： Sulfurization time,Cu2ZnSnS4 (CZTS),Two-stage method,Sputtering,Sulfurization temperature,Kesterite
更新于2025-09-19 17:15:36
-
Studying the influence of deposition temperature and nitrogen contents on the structural, optical, and electrical properties of N-doped SnO2 films prepared by direct current magnetron sputtering
摘要： This report focuses on studying and investigating in detail the structural, electrical, and optical properties of p-type N-doped SnO2 (NTO) versus the deposition temperature and nitrogen content. P-type transparent conductive NTO films were deposited on quartz glass substrates using a direct current (DC) magnetron sputtering method. The substitution of oxygen by nitrogen in the SnO2 host lattice was verified using measurements such as X-ray photoelectron spectroscopy. The position of the N3? defect state in the band gap was determined using photoluminescence and ultra-violet-visible spectroscopy measurements. The data for the (110) to (101) rutile lattice planes changed, and the rutile (plane (101)) to cubic (plane (111)) SnO2 phase transition indicated the substitution of oxygen by nitrogen in the SnO2 host lattice. The best p-type conductive properties achieved were 8 × 10?2 Ω cm, 1.36 × 1019 cm?3, and 6.75 cm2 V?1 s?1 for the resistivity, hole concentration, and hole mobility, respectively, for film deposited at the optimum substrate temperature of 300 °C in a gas mixture of Ar and 50% N2.
关键词： deposition temperature,nitrogen content,p-type N-doped SnO2 thin film,X-ray photoelectron spectroscopy,DC magnetron sputtering,X-ray diffraction
更新于2025-09-19 17:15:36
-
[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - High-Volume Production and Non-Destructive Piezo-Property Mapping of 33% SC Doped Aluminium Nitride Thin Films
摘要： Scandium-doped aluminum nitride (ScAlN) thin films with 22% scandium content (Sc0.22Al0.78N) were deposited on a 100-mm sapphire substrate using a sputtering tool. The films exhibit enhanced piezoelectric properties compared to pure AlN, making them promising for microelectromechanical systems (MEMS) applications. The dielectric constant and loss tangent were measured at 100-mm and 20-mm wavelengths, showing values of εr ≈ 11.7 ± 0.2 and tanδ ≈ 0.002 ± 0.001, respectively. These results indicate high potential for voltage manufacturing and sensing devices.
关键词： dielectric properties,piezoelectric,sputtering,ScAlN,thin films,MEMS
更新于2025-09-19 17:15:36