Polyoxometalates（POMs） with Cd-coordination complexes acting as supporting units are rarely reported. The linkage of the supporting units with inorganic building block（polyanion） is generally established on termin...Polyoxometalates（POMs） with Cd-coordination complexes acting as supporting units are rarely reported. The linkage of the supporting units with inorganic building block（polyanion） is generally established on terminal O-atoms, but scarcely via bridging O-atoms. By introducing liquid small organic molecule（pyridine, C5NH5） as assistant ＂structure-directing agent＂, we obtained a novel organic-inorganic hybrid polytungstate,（Hpy）4[Cd（phen）2（P2W18O62）]·nH2O（1, n ≈ 3, py = pyridine, phen = 1,10-phenanthroline）, under hydrothermal conditions. The single-crystal X-ray diffraction analysis shows that 1 is the first compound containing an asymmetric heteropolyanion, [Cd（phen）2（P2W18O62）]4–, a Wells-Dawson-type polyanion monosupported by Cd-coordination complex via di-bridging O-atoms.展开更多
Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transm...Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.展开更多
Amorphous indium-gallium-zinc oxide(a-IGZO)thin films are prepared by pulsed laser deposition and fabricated into thin-film transistor(TFT)devices.In-situ x-ray photoelectron spectroscopy(XPS)illustrates that weakly b...Amorphous indium-gallium-zinc oxide(a-IGZO)thin films are prepared by pulsed laser deposition and fabricated into thin-film transistor(TFT)devices.In-situ x-ray photoelectron spectroscopy(XPS)illustrates that weakly bonded oxygen(O)atoms exist in a-IGZO thin films deposited at high O_(2) pressures,but these can be eliminated by vacuum annealing.The threshold voltage(V_(th))of the a-IGZO TFTs is shifted under positive gate bias,and the Vth shift is positively related to the deposition pressure.A temperature variation experiment in the range of 20 K-300 K demonstrates that an activation energy of 144 meV is required for the Vth shift,which is close to the activation energy required for the migration of weakly bonded O atoms in a-IGZO thin films.Accordingly,the Vth shift is attributed to the acceptor-like states induced by the accumulation of weakly bonded O atoms at the a-IGZO/SiO_(2) interface under positive gate bias.These results provide an insight into the mechanism responsible for the Vth shift of the a-IGZO TFTs and help in the production of reliable designs.展开更多
Aliphatic amine N-oxides, particularly （CH<sub>3</sub>）<sub>3</sub>NO, have been widely used as O-atom transfer reagents in organometallic chemistry. Recently the systematic kinetic studies o...Aliphatic amine N-oxides, particularly （CH<sub>3</sub>）<sub>3</sub>NO, have been widely used as O-atom transfer reagents in organometallic chemistry. Recently the systematic kinetic studies on O-atom transfer reactions have been reported in detail. However, little is known about the use of pyridine N-oxides and the related aromatic amine N-oxides as O-atom transfer reagents in organometallic chemistry, and no kinetic or展开更多
基金supported by the Foundation of Education Department of Fujian Province(Nos.JB12199 and JA11245)the National Natural Science Foundation of China(Nos.21233004 and 40972035)
文摘Polyoxometalates（POMs） with Cd-coordination complexes acting as supporting units are rarely reported. The linkage of the supporting units with inorganic building block（polyanion） is generally established on terminal O-atoms, but scarcely via bridging O-atoms. By introducing liquid small organic molecule（pyridine, C5NH5） as assistant ＂structure-directing agent＂, we obtained a novel organic-inorganic hybrid polytungstate,（Hpy）4[Cd（phen）2（P2W18O62）]·nH2O（1, n ≈ 3, py = pyridine, phen = 1,10-phenanthroline）, under hydrothermal conditions. The single-crystal X-ray diffraction analysis shows that 1 is the first compound containing an asymmetric heteropolyanion, [Cd（phen）2（P2W18O62）]4–, a Wells-Dawson-type polyanion monosupported by Cd-coordination complex via di-bridging O-atoms.
基金Project supported by the National Natural Science Foundation of China(Grant No.61106060)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.Y2YF028001)the National High Technology Research and Development Program of China(Grant No.2012AA052401)
文摘Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51771144 and 62104189)the Natural Science Foundation of Shaanxi Province,China(Grant Nos.2021JC-06,2019TD-020,and 2019JLM-30)+1 种基金the China Postdoctoral Science Foundation(Grant No.2020M683483)the Fundamental scientific research business expenses of Xi'an Jiaotong University(Grant No.XZY022020017).
文摘Amorphous indium-gallium-zinc oxide(a-IGZO)thin films are prepared by pulsed laser deposition and fabricated into thin-film transistor(TFT)devices.In-situ x-ray photoelectron spectroscopy(XPS)illustrates that weakly bonded oxygen(O)atoms exist in a-IGZO thin films deposited at high O_(2) pressures,but these can be eliminated by vacuum annealing.The threshold voltage(V_(th))of the a-IGZO TFTs is shifted under positive gate bias,and the Vth shift is positively related to the deposition pressure.A temperature variation experiment in the range of 20 K-300 K demonstrates that an activation energy of 144 meV is required for the Vth shift,which is close to the activation energy required for the migration of weakly bonded O atoms in a-IGZO thin films.Accordingly,the Vth shift is attributed to the acceptor-like states induced by the accumulation of weakly bonded O atoms at the a-IGZO/SiO_(2) interface under positive gate bias.These results provide an insight into the mechanism responsible for the Vth shift of the a-IGZO TFTs and help in the production of reliable designs.
基金Project supported by the National Natural Science Foundation of China
文摘Aliphatic amine N-oxides, particularly （CH<sub>3</sub>）<sub>3</sub>NO, have been widely used as O-atom transfer reagents in organometallic chemistry. Recently the systematic kinetic studies on O-atom transfer reactions have been reported in detail. However, little is known about the use of pyridine N-oxides and the related aromatic amine N-oxides as O-atom transfer reagents in organometallic chemistry, and no kinetic or
