The structural and surface properties of high-quality epitaxial cubic MgxZn1-xO films deposited by pulsed laser deposition (PLD) were studied by X-ray diffracti on and atomic force microscopy respectively. For films o...The structural and surface properties of high-quality epitaxial cubic MgxZn1-xO films deposited by pulsed laser deposition (PLD) were studied by X-ray diffracti on and atomic force microscopy respectively. For films of about 500nm thick, sca ns over a 30μm × 30μm area revealed a surface roughness Ra of about 100nm. Th is relatively large surface roughness is primarily attributed to the particulate and outgrowth during the PLD process. A good epitaxial growth on LaAlO3 (LAO ) (100) substrates, however has been obtained for composition x = 0.9, 0.7 and 0 .5 with the heteroepitaxial relationship of (100)■∥(100)LAO (out-of-plane) and (011)■∥(010)LAO (in-plane). These structural qualities suggest that cubic Mgx Zn1-xO alloys films have good potential in a variety of optoelectronic device ap plications.展开更多
MgxZn1-xO thin films have been prepared on silicon substrates by radio frequency magnetron sputtering at 60℃. The thin films have hexagonal wurtzite single-phase structure and a preferred orientation with the c-axis ...MgxZn1-xO thin films have been prepared on silicon substrates by radio frequency magnetron sputtering at 60℃. The thin films have hexagonal wurtzite single-phase structure and a preferred orientation with the c-axis perpendicular to the substrates. The refractive indices of MgxZn1-xO films are studied at room temperature by spectroscopic ellipsometry over the wavelength range of 400-760nm at the incident angle of 70°. Both absorption coefficients and optical band gaps of MgxZn1-xO films are determined by the transmittance spectra. While Mg content is increasing, the absorption edges of MgxZn1-xO films shift to higher energies and band gaps linearly increase from 3.24. eV at x=0 to 3.90 eV at x=0.30. These results provide important information for the design and modelling of ZnO/ MgxZn1-xO heterostructure optoelectronic devices.展开更多
Homogeneous, crack-free SrNbxTi1-xO3 thin films on （110） silicon substrates were successfully fabricated by sol-gel processing. The optimum route and conditions were systematically investigated. Sr（OAc）2 glacial a...Homogeneous, crack-free SrNbxTi1-xO3 thin films on （110） silicon substrates were successfully fabricated by sol-gel processing. The optimum route and conditions were systematically investigated. Sr（OAc）2 glacial acetic acid solution, after being refluxed and reacted with tartrate, formed Sr（OAc）2（C4H6O6）2; Ti（OBu）4 formed Ti（OAc）4-x（AcAc）x. after having the ligand partially exchanged with AcAc, while Nb（OC2H5）5 formed （OAc）2Nb（AcAc） （C4H606）by exchanging of ligand in glacial acetic acid with （CH3CO）2O. All the metal species after undergoing partial hydrolysis and polymerization with hydroxyl or oxygen, formed SrNb,Ti1-xO3 cluster sol. Methyl cellulose （MCL） caused SrNbxTi1-xO3 sol to have polymeric structure and easily form films. SrNbxTi1-xO3 films with perovskite were subsequently formed after being annealed at 650-750 ℃ for 60 min in 25% N2＋75% H2 （volume ratio） atmosphere. Resistivity of the SrNb0.1 Ti0.9O3 films at room temperature was 64 μΩ·cm, a particular T2 temperature dependence of the resistivity, from 25 K up to room temperature, was observed.展开更多
文摘The structural and surface properties of high-quality epitaxial cubic MgxZn1-xO films deposited by pulsed laser deposition (PLD) were studied by X-ray diffracti on and atomic force microscopy respectively. For films of about 500nm thick, sca ns over a 30μm × 30μm area revealed a surface roughness Ra of about 100nm. Th is relatively large surface roughness is primarily attributed to the particulate and outgrowth during the PLD process. A good epitaxial growth on LaAlO3 (LAO ) (100) substrates, however has been obtained for composition x = 0.9, 0.7 and 0 .5 with the heteroepitaxial relationship of (100)■∥(100)LAO (out-of-plane) and (011)■∥(010)LAO (in-plane). These structural qualities suggest that cubic Mgx Zn1-xO alloys films have good potential in a variety of optoelectronic device ap plications.
文摘MgxZn1-xO thin films have been prepared on silicon substrates by radio frequency magnetron sputtering at 60℃. The thin films have hexagonal wurtzite single-phase structure and a preferred orientation with the c-axis perpendicular to the substrates. The refractive indices of MgxZn1-xO films are studied at room temperature by spectroscopic ellipsometry over the wavelength range of 400-760nm at the incident angle of 70°. Both absorption coefficients and optical band gaps of MgxZn1-xO films are determined by the transmittance spectra. While Mg content is increasing, the absorption edges of MgxZn1-xO films shift to higher energies and band gaps linearly increase from 3.24. eV at x=0 to 3.90 eV at x=0.30. These results provide important information for the design and modelling of ZnO/ MgxZn1-xO heterostructure optoelectronic devices.
基金Project (No. 2002CB613305) supported by the National Basic Re-search Program (973) of China
文摘Homogeneous, crack-free SrNbxTi1-xO3 thin films on （110） silicon substrates were successfully fabricated by sol-gel processing. The optimum route and conditions were systematically investigated. Sr（OAc）2 glacial acetic acid solution, after being refluxed and reacted with tartrate, formed Sr（OAc）2（C4H6O6）2; Ti（OBu）4 formed Ti（OAc）4-x（AcAc）x. after having the ligand partially exchanged with AcAc, while Nb（OC2H5）5 formed （OAc）2Nb（AcAc） （C4H606）by exchanging of ligand in glacial acetic acid with （CH3CO）2O. All the metal species after undergoing partial hydrolysis and polymerization with hydroxyl or oxygen, formed SrNb,Ti1-xO3 cluster sol. Methyl cellulose （MCL） caused SrNbxTi1-xO3 sol to have polymeric structure and easily form films. SrNbxTi1-xO3 films with perovskite were subsequently formed after being annealed at 650-750 ℃ for 60 min in 25% N2＋75% H2 （volume ratio） atmosphere. Resistivity of the SrNb0.1 Ti0.9O3 films at room temperature was 64 μΩ·cm, a particular T2 temperature dependence of the resistivity, from 25 K up to room temperature, was observed.
