Structural and optical properties of ～ 20 nm Ge nanoislands grown on Si（100） by radio frequency （rI） magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature...Structural and optical properties of ～ 20 nm Ge nanoislands grown on Si（100） by radio frequency （rI） magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature of 600 ℃ for 30 s, 90 s, and 120 s are performed to examine the influence of annealing time on the surface morphology and photoluminescence properties. X-ray diffraction spectra reveal prominent Ge and GeO2 peaks highly sensitive to the annealing time. Atomic force microscope micrographs of the as-grown sample show pyramidal nanoislands with relatively high-density （～ 10^11 cm^-2）. The nanoislands become dome-shaped upon annealing through a coarsening process mediated by Oswald ripening. The room temperature photoluminescence peaks for both as-grown （～ 3.29 eV） and annealed （～ 3.19 eV） samples consist of high intensity and broad emission, attributed to the effect of quantum confinement. The red shift （～ 0.10 eV） of the emission peak is attributed to the change in the size of the Ge nanoislands caused by annealing. Our easy fabrication method may contribute to the development of Ge nanostructure-based optoelectronics.展开更多
ZnO thin films were deposited on Si（111） substrates through a radio frequency （rf） magnetron sputtering system. Then the samples were annealed at different temperatures in air ambience and ammonia ambience respect...ZnO thin films were deposited on Si（111） substrates through a radio frequency （rf） magnetron sputtering system. Then the samples were annealed at different temperatures in air ambience and ammonia ambience respectively. The structure and composition of the ZnO films were studied by X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. The morphology of the samples was studied by scanning electron microscopy （SEM）. Measured results show that ZnO films with hexagonal wurtzite structure were grown on Si（111） substrates when annealed in the two ambiences. The volatilization process of ZnO in the ammonia ambience at high temperature was discussed and the mechanism of the reaction was analyzed.展开更多
Indium tin oxide（ITO）thin films（100±10nm）were deposited on PC（polycarbonate）and glass substrates by rf（radio-frequency）mannetron spuutering.The oxygen content of the ITO films was changed by variation of ...Indium tin oxide（ITO）thin films（100±10nm）were deposited on PC（polycarbonate）and glass substrates by rf（radio-frequency）mannetron spuutering.The oxygen content of the ITO films was changed by variation of the sputtering gas composition.All the other deposition parameters were kept constant.The sheet resistance.optical transmittance and microstructure of ITO films were investigated using a four-point probe.spectrophotometer,X-ray diffractometer（XRD）and atomic force microscope（AFM）.Sheet resistances for the ITO films with optical transmittance more than 75% on PC substrates varied from 40Ω/cm^2 to more than 104 Ω/cm^2 with increasing oxygen partial pressure from O to about 2%.The same tendeney of sheet resistances increasing with increasing oxygen partial pressure was observed on glass substrates.The X-ray diffraction data indicated polycrystalline filns with grain orientations predominantly along（440）and （422）directions.The intensities of （440）and （422）peaks increased slightly with the increase of oxygen partial pressure both on PC and glass substrates.The AFM images show that the ITO films on PC substrates were dense and uniform.The average grain size of the films was about 40nm.展开更多
High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic targe...High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.展开更多
Using a radio-frequency reactive magnetron sputtering technique, a series of the single-phased Ag20 films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2：3 by changing substrate temperature ...Using a radio-frequency reactive magnetron sputtering technique, a series of the single-phased Ag20 films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2：3 by changing substrate temperature （Ts）. Effects of the Ts on the microstructure and optical properties of the films are investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The single-phased Ag20 films deposited at values of Ts below 200℃ are （111） preferentially oriented, which may be due to the smallest free energy of the （111） crystalline face. The film crystallization becomes poor as the value of Ts increases from 100℃ to 225℃. In particular, the Ag20 film deposited at Ts=225℃ loses the （111） preferential orientation. Correspondingly, the film surface morphology obviously evolves from a uniform and compact surface structure to a loose and gullied surface structure. With the increase of Ts value, the transmissivity and the reflectivity of the films in the transparent region are gradually reduced, while the absorptivity gradually increases, which may be attributed to an evolution of the crystalline structure and the surface morphology of the films.展开更多
In order to obtain high quality NiO thin film grown with the radio-frequency magnetron sputtering method, the influence of O/Ar ratio on the structure, band-gap, resistivity and optical transmittance of NiO thin films...In order to obtain high quality NiO thin film grown with the radio-frequency magnetron sputtering method, the influence of O/Ar ratio on the structure, band-gap, resistivity and optical transmittance of NiO thin films were studied. It was found that the obtained NiO thin film showed （111） preferred orientation and higher transparency in the visible region. With the increasing of O/ Ar ratio from 1：7 to 8： 2, the optical transmittance of NiO thin films decreased and the optical band- gap was between 3. 4 eV and 3. 7 eV, and the sheet resistivity decreased from 5. 4 ~ 107 Ω/ to 1.0 × 10^5 Ω/[]. Our study shows that the properties of NiO thin films can be adjusted in a wide range by adjusting the O/At ratio in the sputtering process.展开更多
He-charged oxide dispersion strengthened （ODS） FeCrNi fills were prepared by a radiofrequency （RF） plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C.As a comparison,He-charged FeCrN...He-charged oxide dispersion strengthened （ODS） FeCrNi fills were prepared by a radiofrequency （RF） plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C.As a comparison,He-charged FeCrNi films were also fabricated at the same conditions through direct current （DC） plasma magnetron sputtering.The doping of He atoms and Y2O3 in the FeCrNi fills was realized by the high backscattered rate of He ions and Y2O3/FeCrNi composite target sputtering method,respectively.Inductive coupled plasma （ICP） and x-ray photoelectron spectroscopy （XPS） analysis confirmed the existence of Y2O3 in FeCrNi fills,and Y2O3 content hardly changed with sputtering He/Ar ratio.Cross-sectional scanning electron microscopy （SEM） shows that the FeCrNi films were composed of dense colunnarnanocrystallines and the thickness of the films was obviously dependent on He/Ar ratio.Nanoindentation measurements revealed that the FeCrNi films fabricated through DC/RF plasma magnetron sputtering methods exhibited similar hardness values at each He/Ar ratio,while the dispersion of Y2O3 apparently increased the hardness of the fills.Elastic recoil detection （ERD） showed that DC/RF magnetron sputtered FeCrNi films contained similar He amounts （～17 at.%）.Compared with the minimal change of He level with depth in DC-sputtered films,the He amount decreases gradually in depth in the RF-sputtered fills.The Y2O3-doped FeCrNi films were shown to exhibit much smaller amounts of He owing to the lower backscattering possibility of Y2O3 and the inhibition effect of nano-sized Y2O3 particles on the He element.展开更多
60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin ...60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin film with the largest UV cut-off wavelength. The sample films with CeO2：TiO2=60：40 were heated at 773 K, 873 K, 973 K for 30 min. These films are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and X-ray photoelectron spectroscopy and spectrometer （XPS）. XRD analysis proves that the addition of TiO2 to CeO2 changed the crystalline state of CeO2. But the UV absorption effect of CeO2-TiO2 films with CeO2 crystallite phase is inferior to that of the amorphous phase CeO2-TiO2 films. XPS analysis also indicates that the amorphous phase CeO2-TiO2 films have the most Ce3＋ content in these films. Amorphous phase and crystalline phase of the CeO2-TiO2 films have different effects on UV absorption of the thin films.展开更多
Metallic copper（Cu） films were deposited on a Si （100） substrate by unbalanced magnetron sputtering enhanced by radio-frequency plasma and external magnetic field confinement. The morphology and structure of the f...Metallic copper（Cu） films were deposited on a Si （100） substrate by unbalanced magnetron sputtering enhanced by radio-frequency plasma and external magnetic field confinement. The morphology and structure of the films were examined by scanning electron microscopy （SEM）, atomic force microscope （AFM） and X-ray diffraction （XRD）. The surface average roughness of the deposited Cu films was characterized by AFM data and resistivity was measured by a four-point probe. The results show that the Cu films deposited with radio-frequency discharge enhanced ionization and external magnetic field confinement have a smooth surface, low surface roughness and low resistivity. The reasons may be that the radio-frequency discharge and external magnetic field enhance the plasma density, which further improves the ion bombardment effect under the same bias voltage conditions. Ion bombardment can obviously influence the growth features and characteristics of the deposited Cu films.展开更多
Tungsten doped indium oxide （IWO） thin films were deposited on glass substrate at room temperature by radio frequency reactive magnetron sputtering. Chemical states analysis was carried out, indicating that valence ...Tungsten doped indium oxide （IWO） thin films were deposited on glass substrate at room temperature by radio frequency reactive magnetron sputtering. Chemical states analysis was carried out, indicating that valence states of element W in the films were W4＋ and W6＋. The effects of sputtering power and film thickness on the surface morphology, optical and electrical properties of IWO thin films were investigated. The IWO thin films had high transmittance in near infrared （NIR） spectral range. The resistivity, carrier mobility and carrier concentration owned their respective optimum values as sputtering power and thickness changed. The asdeposited IWO film with the minimum resistivity of 3.23 × 10^-4 Ω cm was obtained at a sputtering power of 50 W, with carrier mobility of 27.1 cm2 V-1 s-1, carrier concentration of 7.15 × 10^20 cm-3, average transmittance about 80% in visible region and above 75% in NIR region. It may meet the application requirement of high conductivity and transparency in NIR wavelength region.展开更多
基金supported by the International Doctoral Fellowship (IDF), Ibnu Sina Institute for Fundamental Science Study and research grants of MoHE GUP. Vot No. 02H94 and 07J80
文摘Structural and optical properties of ～ 20 nm Ge nanoislands grown on Si（100） by radio frequency （rI） magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature of 600 ℃ for 30 s, 90 s, and 120 s are performed to examine the influence of annealing time on the surface morphology and photoluminescence properties. X-ray diffraction spectra reveal prominent Ge and GeO2 peaks highly sensitive to the annealing time. Atomic force microscope micrographs of the as-grown sample show pyramidal nanoislands with relatively high-density （～ 10^11 cm^-2）. The nanoislands become dome-shaped upon annealing through a coarsening process mediated by Oswald ripening. The room temperature photoluminescence peaks for both as-grown （～ 3.29 eV） and annealed （～ 3.19 eV） samples consist of high intensity and broad emission, attributed to the effect of quantum confinement. The red shift （～ 0.10 eV） of the emission peak is attributed to the change in the size of the Ge nanoislands caused by annealing. Our easy fabrication method may contribute to the development of Ge nanostructure-based optoelectronics.
基金This work was financially supported by the Key Research Program of National Natural Science Foundation of China (Nos.90301002 and 90201025).
文摘ZnO thin films were deposited on Si（111） substrates through a radio frequency （rf） magnetron sputtering system. Then the samples were annealed at different temperatures in air ambience and ammonia ambience respectively. The structure and composition of the ZnO films were studied by X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. The morphology of the samples was studied by scanning electron microscopy （SEM）. Measured results show that ZnO films with hexagonal wurtzite structure were grown on Si（111） substrates when annealed in the two ambiences. The volatilization process of ZnO in the ammonia ambience at high temperature was discussed and the mechanism of the reaction was analyzed.
文摘Indium tin oxide（ITO）thin films（100±10nm）were deposited on PC（polycarbonate）and glass substrates by rf（radio-frequency）mannetron spuutering.The oxygen content of the ITO films was changed by variation of the sputtering gas composition.All the other deposition parameters were kept constant.The sheet resistance.optical transmittance and microstructure of ITO films were investigated using a four-point probe.spectrophotometer,X-ray diffractometer（XRD）and atomic force microscope（AFM）.Sheet resistances for the ITO films with optical transmittance more than 75% on PC substrates varied from 40Ω/cm^2 to more than 104 Ω/cm^2 with increasing oxygen partial pressure from O to about 2%.The same tendeney of sheet resistances increasing with increasing oxygen partial pressure was observed on glass substrates.The X-ray diffraction data indicated polycrystalline filns with grain orientations predominantly along（440）and （422）directions.The intensities of （440）and （422）peaks increased slightly with the increase of oxygen partial pressure both on PC and glass substrates.The AFM images show that the ITO films on PC substrates were dense and uniform.The average grain size of the films was about 40nm.
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University, Ministry of Education, China (No.IRT0547)
文摘High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60807001)the Foundation of Henan Educational Committee,China (Grant No. 2010A140017)the National Basic Research Program of China (Grant No. 2011CB201605)
文摘Using a radio-frequency reactive magnetron sputtering technique, a series of the single-phased Ag20 films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2：3 by changing substrate temperature （Ts）. Effects of the Ts on the microstructure and optical properties of the films are investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The single-phased Ag20 films deposited at values of Ts below 200℃ are （111） preferentially oriented, which may be due to the smallest free energy of the （111） crystalline face. The film crystallization becomes poor as the value of Ts increases from 100℃ to 225℃. In particular, the Ag20 film deposited at Ts=225℃ loses the （111） preferential orientation. Correspondingly, the film surface morphology obviously evolves from a uniform and compact surface structure to a loose and gullied surface structure. With the increase of Ts value, the transmissivity and the reflectivity of the films in the transparent region are gradually reduced, while the absorptivity gradually increases, which may be attributed to an evolution of the crystalline structure and the surface morphology of the films.
基金Supported by the National Natural Science Foundation of China(11004016)
文摘In order to obtain high quality NiO thin film grown with the radio-frequency magnetron sputtering method, the influence of O/Ar ratio on the structure, band-gap, resistivity and optical transmittance of NiO thin films were studied. It was found that the obtained NiO thin film showed （111） preferred orientation and higher transparency in the visible region. With the increasing of O/ Ar ratio from 1：7 to 8： 2, the optical transmittance of NiO thin films decreased and the optical band- gap was between 3. 4 eV and 3. 7 eV, and the sheet resistivity decreased from 5. 4 ~ 107 Ω/ to 1.0 × 10^5 Ω/[]. Our study shows that the properties of NiO thin films can be adjusted in a wide range by adjusting the O/At ratio in the sputtering process.
基金financially supported by National Natural Science Foundation of China(No.11374299)
文摘He-charged oxide dispersion strengthened （ODS） FeCrNi fills were prepared by a radiofrequency （RF） plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C.As a comparison,He-charged FeCrNi films were also fabricated at the same conditions through direct current （DC） plasma magnetron sputtering.The doping of He atoms and Y2O3 in the FeCrNi fills was realized by the high backscattered rate of He ions and Y2O3/FeCrNi composite target sputtering method,respectively.Inductive coupled plasma （ICP） and x-ray photoelectron spectroscopy （XPS） analysis confirmed the existence of Y2O3 in FeCrNi fills,and Y2O3 content hardly changed with sputtering He/Ar ratio.Cross-sectional scanning electron microscopy （SEM） shows that the FeCrNi films were composed of dense colunnarnanocrystallines and the thickness of the films was obviously dependent on He/Ar ratio.Nanoindentation measurements revealed that the FeCrNi films fabricated through DC/RF plasma magnetron sputtering methods exhibited similar hardness values at each He/Ar ratio,while the dispersion of Y2O3 apparently increased the hardness of the fills.Elastic recoil detection （ERD） showed that DC/RF magnetron sputtered FeCrNi films contained similar He amounts （～17 at.%）.Compared with the minimal change of He level with depth in DC-sputtered films,the He amount decreases gradually in depth in the RF-sputtered fills.The Y2O3-doped FeCrNi films were shown to exhibit much smaller amounts of He owing to the lower backscattering possibility of Y2O3 and the inhibition effect of nano-sized Y2O3 particles on the He element.
基金the National Natural Science Foundation of China(No.51032005)the Fundamental Research Funds for the Central Universities(Wuhan University of Technology)+1 种基金the China Postdoctoral Science Foundation(No.2012M511285)the Fund for the Young Innovative Team(Hubei University of Education)(No.2012KQ05)
文摘60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin film with the largest UV cut-off wavelength. The sample films with CeO2：TiO2=60：40 were heated at 773 K, 873 K, 973 K for 30 min. These films are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and X-ray photoelectron spectroscopy and spectrometer （XPS）. XRD analysis proves that the addition of TiO2 to CeO2 changed the crystalline state of CeO2. But the UV absorption effect of CeO2-TiO2 films with CeO2 crystallite phase is inferior to that of the amorphous phase CeO2-TiO2 films. XPS analysis also indicates that the amorphous phase CeO2-TiO2 films have the most Ce3＋ content in these films. Amorphous phase and crystalline phase of the CeO2-TiO2 films have different effects on UV absorption of the thin films.
基金National Natural Science Foundation of China(Nos.50277003,10505005)
文摘Metallic copper（Cu） films were deposited on a Si （100） substrate by unbalanced magnetron sputtering enhanced by radio-frequency plasma and external magnetic field confinement. The morphology and structure of the films were examined by scanning electron microscopy （SEM）, atomic force microscope （AFM） and X-ray diffraction （XRD）. The surface average roughness of the deposited Cu films was characterized by AFM data and resistivity was measured by a four-point probe. The results show that the Cu films deposited with radio-frequency discharge enhanced ionization and external magnetic field confinement have a smooth surface, low surface roughness and low resistivity. The reasons may be that the radio-frequency discharge and external magnetic field enhance the plasma density, which further improves the ion bombardment effect under the same bias voltage conditions. Ion bombardment can obviously influence the growth features and characteristics of the deposited Cu films.
基金financially supported by the National Natural Science Foundation of China(No.50902006)Aviation Science Foundation of China(2012zf51066)
文摘Tungsten doped indium oxide （IWO） thin films were deposited on glass substrate at room temperature by radio frequency reactive magnetron sputtering. Chemical states analysis was carried out, indicating that valence states of element W in the films were W4＋ and W6＋. The effects of sputtering power and film thickness on the surface morphology, optical and electrical properties of IWO thin films were investigated. The IWO thin films had high transmittance in near infrared （NIR） spectral range. The resistivity, carrier mobility and carrier concentration owned their respective optimum values as sputtering power and thickness changed. The asdeposited IWO film with the minimum resistivity of 3.23 × 10^-4 Ω cm was obtained at a sputtering power of 50 W, with carrier mobility of 27.1 cm2 V-1 s-1, carrier concentration of 7.15 × 10^20 cm-3, average transmittance about 80% in visible region and above 75% in NIR region. It may meet the application requirement of high conductivity and transparency in NIR wavelength region.
