Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite （7-Cu2S） phas...Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite （7-Cu2S） phase. The atomic force microscopy images indicate that the film exhibits nanoparticles with an average size of nearly 44 nm. Specrtophotometric measurements for the transmittance and reflectance are carried out at normal incidence in a spectral wavelength range of 450 nm-2500 nm. The refractive index, n, as well as the absorption index, k is calculated. Some dispersion parameters are determined. The analyses of el and e2 reveal several absorption peaks. The analysis of the spectral behavior of the absorption coefficient, c~, in the absorption region reveals direct and indirect allowed transitions. The dark electrical resistivity is studied as a function of film thickness and temperature. Tellier＇s model is adopted for determining the mean free path and bulk resistance.展开更多
Ni0.4Cu0.2Zn0.4Fe2O4 thin films were fabricated on Si substrates by using the sol-gel method and rapid thermal annealing （RTA）, and their magnetic properties and crystalline structures were investigated. The samples...Ni0.4Cu0.2Zn0.4Fe2O4 thin films were fabricated on Si substrates by using the sol-gel method and rapid thermal annealing （RTA）, and their magnetic properties and crystalline structures were investigated. The samples calcined at and above 600 ℃ have a single-phase spinel structure and the average grain size of the sample calcined at 600 ℃ is about 20 nm. The initial permeability μi, saturation magnetization M and coercivity H of the samples increase with the increasing calcination temperature. The sample calcined at 600 ℃ exhibits an excellent soft magnetic performance, which has μi=33.97 （10 MHz）, Hc=15.62 Oe and Ms=228.877 emu/cm^3. Low-temperature annealing can enhance the magnetic properties of the samples. The work shows that using the sol-gel method in conjunction with RTA is a promising way to fabricate integrated thin-film devices.展开更多
Copper nitride（Cu3 N） thin films display typical trans-rhenium trioxide structures. They exhibit excellent physical properties, low cost, nontoxicity, and high stability under room temperature. However, they possess...Copper nitride（Cu3 N） thin films display typical trans-rhenium trioxide structures. They exhibit excellent physical properties, low cost, nontoxicity, and high stability under room temperature. However, they possess low-thermal decomposition temperature, and their lattice constant often changes significantly with prepared technologies or techniques, thereby enabling the transformation from insulators to semiconductors and even conductors. Moreover, Cu3 N thin films are becoming the new research hotspot of optical information storage devices, microelectronic semiconductor materials, and new energy materials. In this study, existing major prepared technologies of Cu3 N thin films are summarized. Influences of prepared technologies of Cu3 N thin films on crystal structure of films, as well as influences of prepared conditions and methods（e.g., nitrogen pressure, deposition power, substrate temperature, and element addition） on crystal structure and optical, electrical, and thermal properties of films were analyzed. The relationship between crystal structure and physical properties of Cu3 N thin films was explored. Finally,applications of Cu3 N thin films in photoelectricity, energy sources, nanometer devices, and other fields were discussed.展开更多
Undoped and Zn-doped Cu2O films were deposited onto glass substrates using successive ionic layer adsorption and reaction（SILAR） technique with different Zn doping levels（0, 1, 2, 3, 5 and 10 wt%）. The structural,...Undoped and Zn-doped Cu2O films were deposited onto glass substrates using successive ionic layer adsorption and reaction（SILAR） technique with different Zn doping levels（0, 1, 2, 3, 5 and 10 wt%）. The structural,optical, and surface morphological studies were carried out and reported. The structural study revealed that the crystalline quality is gradually enhanced up to 5 wt% of Zn doping level, and then quality begins to degrade for further increase in doping level. Moreover, the preferential orientation changes from（111） to（110） for the highest doping level were examined. Optical study shows that the transmittance（65%） and optical band gap values are maximum（2.41 e V） when the Zn doping level is at 5 wt%. The photoluminescence study confirms the presence of various defects in the Cu2O matrix and also the variation obtained in the optical band gap from the transmittance data. SEM images revealed the annealinginduced changes in the surface morphology of the films.展开更多
文摘Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite （7-Cu2S） phase. The atomic force microscopy images indicate that the film exhibits nanoparticles with an average size of nearly 44 nm. Specrtophotometric measurements for the transmittance and reflectance are carried out at normal incidence in a spectral wavelength range of 450 nm-2500 nm. The refractive index, n, as well as the absorption index, k is calculated. Some dispersion parameters are determined. The analyses of el and e2 reveal several absorption peaks. The analysis of the spectral behavior of the absorption coefficient, c~, in the absorption region reveals direct and indirect allowed transitions. The dark electrical resistivity is studied as a function of film thickness and temperature. Tellier＇s model is adopted for determining the mean free path and bulk resistance.
基金the National Natural Science Foundation of China (No. 90607021).
文摘Ni0.4Cu0.2Zn0.4Fe2O4 thin films were fabricated on Si substrates by using the sol-gel method and rapid thermal annealing （RTA）, and their magnetic properties and crystalline structures were investigated. The samples calcined at and above 600 ℃ have a single-phase spinel structure and the average grain size of the sample calcined at 600 ℃ is about 20 nm. The initial permeability μi, saturation magnetization M and coercivity H of the samples increase with the increasing calcination temperature. The sample calcined at 600 ℃ exhibits an excellent soft magnetic performance, which has μi=33.97 （10 MHz）, Hc=15.62 Oe and Ms=228.877 emu/cm^3. Low-temperature annealing can enhance the magnetic properties of the samples. The work shows that using the sol-gel method in conjunction with RTA is a promising way to fabricate integrated thin-film devices.
基金the National Natural Science Foundation of China (No. 11364011)Guangxi Natural Science Foundation (Nos. 2015GXNSFAA139004, and 2017GXNSFAA198121)
文摘Copper nitride（Cu3 N） thin films display typical trans-rhenium trioxide structures. They exhibit excellent physical properties, low cost, nontoxicity, and high stability under room temperature. However, they possess low-thermal decomposition temperature, and their lattice constant often changes significantly with prepared technologies or techniques, thereby enabling the transformation from insulators to semiconductors and even conductors. Moreover, Cu3 N thin films are becoming the new research hotspot of optical information storage devices, microelectronic semiconductor materials, and new energy materials. In this study, existing major prepared technologies of Cu3 N thin films are summarized. Influences of prepared technologies of Cu3 N thin films on crystal structure of films, as well as influences of prepared conditions and methods（e.g., nitrogen pressure, deposition power, substrate temperature, and element addition） on crystal structure and optical, electrical, and thermal properties of films were analyzed. The relationship between crystal structure and physical properties of Cu3 N thin films was explored. Finally,applications of Cu3 N thin films in photoelectricity, energy sources, nanometer devices, and other fields were discussed.
基金given by the University Grants Commission of India through the Major Research Project [UGC-MRP: F. No. 41-937/2012(SR)]
文摘Undoped and Zn-doped Cu2O films were deposited onto glass substrates using successive ionic layer adsorption and reaction（SILAR） technique with different Zn doping levels（0, 1, 2, 3, 5 and 10 wt%）. The structural,optical, and surface morphological studies were carried out and reported. The structural study revealed that the crystalline quality is gradually enhanced up to 5 wt% of Zn doping level, and then quality begins to degrade for further increase in doping level. Moreover, the preferential orientation changes from（111） to（110） for the highest doping level were examined. Optical study shows that the transmittance（65%） and optical band gap values are maximum（2.41 e V） when the Zn doping level is at 5 wt%. The photoluminescence study confirms the presence of various defects in the Cu2O matrix and also the variation obtained in the optical band gap from the transmittance data. SEM images revealed the annealinginduced changes in the surface morphology of the films.
