SrTiOs （STO） thin films were deposited on p-Si（100） substrates at various substrate temperatures from 300℃ to 700℃ by radio frequency （RF） magnetron sputtering technique. Their structure and electrical propert...SrTiOs （STO） thin films were deposited on p-Si（100） substrates at various substrate temperatures from 300℃ to 700℃ by radio frequency （RF） magnetron sputtering technique. Their structure and electrical properties were investigated. It was found that the transition from amorphous phase to polycrystalline phase occurred at the substrate temperatures 300-400℃. Their crystallinity became better when the substrate temperatures further increased. The dielectric and leakage current measurements were carried out by using the Si/STO/Pt metal-insulator-semiconductor （MIS） structures at room temperature. It was found that the fixed charge density decreased and both the interface trap density and the dielectric constant increased when the substrate temperatures were increased. The leakage current mechanisms for STO MIS structures with STO films prepared at 700℃ followed the space charge limited current （SCLC） under the low applied electric field and the Poole-Frenkel emission under the high one. In addition, the resistivity for films prepared at 700℃ was higher than 10^11Ω.cm under the voltage lower than 10V （corresponding to the electric field of 1.54×10^3kV.cm^-1）. It suggested that the STO films prepared at 700℃ were suitable for acting as the insulator of metal-ferroelectric-insulator-semiconductor （MFIS） structures.展开更多
The alternation from bipolar to unipolar resistive switching is observed in perovskite La0.01Sr0.99TiO3 thin films. These two switching modes can be activated separately depending on the compliance current （Icomp） d...The alternation from bipolar to unipolar resistive switching is observed in perovskite La0.01Sr0.99TiO3 thin films. These two switching modes can be activated separately depending on the compliance current （Icomp） during the electroforming process： with a higher Icomp （5 mA） the unipolar resistance switching behavior is measured, while the bipolar resistance switching behavior is observed with a lower Icomp （1 mA）. On the basis of I–V characteristics, the switching mechanisms for the URS and BRS modes are considered as being a change in the Schottky-like barrier height and/or width at the Pt/La-SrTiO3 interface and the formation and disruption of conduction filaments, respectively.展开更多
SrTiO3 thin film was successfully prepared on the functionalized organic self-assembled monolayers（SAMs） by the Liquid Phase Deposition（LPD） method.The as-prepared samples were characterized by X-ray diffraction（...SrTiO3 thin film was successfully prepared on the functionalized organic self-assembled monolayers（SAMs） by the Liquid Phase Deposition（LPD） method.The as-prepared samples were characterized by X-ray diffraction（XRD）,atomic force microscope（AFM）,scanning electron microscopy（SEM） and metallographic microscope.Measurement of contact angle showed that the hydrophobe substrate was changed into hydrophile by UV irradiation.AFM photographs of octadecyl-trichloro-silane self-assembled monolayer（OTS-SAM） surface approved that UV irradiation did change the morphology of OTS monolayer and provided evidence for the conversion of hydrophilic characteristic.Photographs of Metallographic Microscope showed that OTS-SAM had an active effect on the deposition of SrTiO3 thin film.XRD and SEM indicated that the thin film was of pure cubic phase SrTiO3 and composed of nanosized grains with a size in the range of 100-500 nm.The formation mechanism of the SrTiO3 film was proposed.展开更多
Stainless steel-doped SrTiO3 thin films were fabricated by laser molecular beam epitaxy (L-MBE). Nonlinear optical property of the thin film was measured by the single beam Z-scan technique at the wavelength of 532 nm...Stainless steel-doped SrTiO3 thin films were fabricated by laser molecular beam epitaxy (L-MBE). Nonlinear optical property of the thin film was measured by the single beam Z-scan technique at the wavelength of 532 nm. Two two-phonon absorption coefficient and nonlinear refractive index were determined to be 9.37 x 10-7 m/W and 1.55 x 10-6 esu, respectively. The merit figure T was calculated to be 1.8, satisfying condition T < 1 for an optical switch. The thin film has a very promising prospect for the applications in optical device.展开更多
The identification of the switching location has been a key technology to tune the physical properties of unipolar resistive switching（RS） cells.Here we report the RS properties of Au/Ni O/Sr Ti O3（STO）/Pt memory ...The identification of the switching location has been a key technology to tune the physical properties of unipolar resistive switching（RS） cells.Here we report the RS properties of Au/Ni O/Sr Ti O3（STO）/Pt memory cells.The switching repeatability is closely related to the applied bias polarity,which is different from the scenario of the Au/STO/Pt cells reported in our previous researches.The high resistance in positive bias is greater than that in negative bias.The R（T）–R0I^2 R（T） plot of the on-state I–V curve shows a regular shape only with a slight bend and an abnormal shape with an abrupt increase and decrease under negative and positive bias,respectively.These comparative experimental results reveal that the conductance filament consisting of oxygen vacancies grows from the cathode to the anode.The spatial RS location is identified with the weaker part along the conductance filament length direction,which should be near the Ni O/STO interface and STO/Pt interface under positive and negative bias,respectively.展开更多
基金Project supported by National Natural Science Foundation （Grant Nos 60221502 and 60223006） and Shanghai R＆D Foundation for Applied Materials （Grant No 0316）.
文摘SrTiOs （STO） thin films were deposited on p-Si（100） substrates at various substrate temperatures from 300℃ to 700℃ by radio frequency （RF） magnetron sputtering technique. Their structure and electrical properties were investigated. It was found that the transition from amorphous phase to polycrystalline phase occurred at the substrate temperatures 300-400℃. Their crystallinity became better when the substrate temperatures further increased. The dielectric and leakage current measurements were carried out by using the Si/STO/Pt metal-insulator-semiconductor （MIS） structures at room temperature. It was found that the fixed charge density decreased and both the interface trap density and the dielectric constant increased when the substrate temperatures were increased. The leakage current mechanisms for STO MIS structures with STO films prepared at 700℃ followed the space charge limited current （SCLC） under the low applied electric field and the Poole-Frenkel emission under the high one. In addition, the resistivity for films prepared at 700℃ was higher than 10^11Ω.cm under the voltage lower than 10V （corresponding to the electric field of 1.54×10^3kV.cm^-1）. It suggested that the STO films prepared at 700℃ were suitable for acting as the insulator of metal-ferroelectric-insulator-semiconductor （MFIS） structures.
基金Project supported by the Key Projects of the National Natural Science Foundation of China(Grant No.11032010)the National Natural Science Foundation of China(Grant Nos.51072171,61274107,61176093,and 11275163)+4 种基金the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT1080)the National Basic Rearch Program of China(Grant No.2012CB326404)the Key Projects of Scientific Research Fund of Hunan Provincial Education Department,China(Grant No.12A129)the Doctoral Program of Higher Education of China(Grant No.20104301110001)the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province,China
文摘The alternation from bipolar to unipolar resistive switching is observed in perovskite La0.01Sr0.99TiO3 thin films. These two switching modes can be activated separately depending on the compliance current （Icomp） during the electroforming process： with a higher Icomp （5 mA） the unipolar resistance switching behavior is measured, while the bipolar resistance switching behavior is observed with a lower Icomp （1 mA）. On the basis of I–V characteristics, the switching mechanisms for the URS and BRS modes are considered as being a change in the Schottky-like barrier height and/or width at the Pt/La-SrTiO3 interface and the formation and disruption of conduction filaments, respectively.
基金Funded by National Natural Science Foundation of China (No. 50672055,50872077)National Key Technology R&D Program (No. 2006BAF02A28)the Graduate Innovation Fund of Shaanxi University of Science and Technology
文摘SrTiO3 thin film was successfully prepared on the functionalized organic self-assembled monolayers（SAMs） by the Liquid Phase Deposition（LPD） method.The as-prepared samples were characterized by X-ray diffraction（XRD）,atomic force microscope（AFM）,scanning electron microscopy（SEM） and metallographic microscope.Measurement of contact angle showed that the hydrophobe substrate was changed into hydrophile by UV irradiation.AFM photographs of octadecyl-trichloro-silane self-assembled monolayer（OTS-SAM） surface approved that UV irradiation did change the morphology of OTS monolayer and provided evidence for the conversion of hydrophilic characteristic.Photographs of Metallographic Microscope showed that OTS-SAM had an active effect on the deposition of SrTiO3 thin film.XRD and SEM indicated that the thin film was of pure cubic phase SrTiO3 and composed of nanosized grains with a size in the range of 100-500 nm.The formation mechanism of the SrTiO3 film was proposed.
基金This work was supported by the National Natural Science Foundation under Grant No. 5001161952.
文摘Stainless steel-doped SrTiO3 thin films were fabricated by laser molecular beam epitaxy (L-MBE). Nonlinear optical property of the thin film was measured by the single beam Z-scan technique at the wavelength of 532 nm. Two two-phonon absorption coefficient and nonlinear refractive index were determined to be 9.37 x 10-7 m/W and 1.55 x 10-6 esu, respectively. The merit figure T was calculated to be 1.8, satisfying condition T < 1 for an optical switch. The thin film has a very promising prospect for the applications in optical device.
基金Project supported by the National Natural Science Foundation of China(Grant No.11404093)the Foundation of Henan Provincial Science and Technology Department,China(Grant No.132102210258)+1 种基金the Research Funding from Henan Province,China(Grant Nos.15A140001,2015GGJS-021,and 17HASTIT014)the Henan University Emerging Cross and Characteristic Discipline Cultivation Program,China(Grant No.xxjc20140016)
文摘The identification of the switching location has been a key technology to tune the physical properties of unipolar resistive switching（RS） cells.Here we report the RS properties of Au/Ni O/Sr Ti O3（STO）/Pt memory cells.The switching repeatability is closely related to the applied bias polarity,which is different from the scenario of the Au/STO/Pt cells reported in our previous researches.The high resistance in positive bias is greater than that in negative bias.The R（T）–R0I^2 R（T） plot of the on-state I–V curve shows a regular shape only with a slight bend and an abnormal shape with an abrupt increase and decrease under negative and positive bias,respectively.These comparative experimental results reveal that the conductance filament consisting of oxygen vacancies grows from the cathode to the anode.The spatial RS location is identified with the weaker part along the conductance filament length direction,which should be near the Ni O/STO interface and STO/Pt interface under positive and negative bias,respectively.
