Recent research results on deep level defects in semi-insulating InP - Application to improve material quality

An apparent defect suppression effect has been observed in InP through an investigation of deep level defects in different semi-insulating (SI) InP materials. Quality improvement of SI-InP based on the defect suppression mechanism is presented.

The role of CeO2-ZrO2 as support in the ZnO-ZnCr2O4 catalysts for autothermal reforming of methanol

Autothermal reforming of methanol for hydrogen production was investigated over ZnO-ZnCr2O4 supported on a series of metal oxides (Al2O3, CeO2, ZrO2 and CeO2-ZrO2)CeO2-ZrO2 mixed oxides with Ce /Zr molar ratio of 4/1 was found to be the optimal support which showed significant effect on the catalytic activity and selectivity. The ZnO-ZnCr2O4/CeO2-ZrO2 and ZnO-ZnCr2O4 catalysts were characterized by XRD, TEM, H-2-TPR and XPS. The results show that CeO2-ZrO2 mixed oxides have significant effect on the catalytic performance and the supported catalyst shows more uniform temperature distribution in the catalyst bed which was mainly due to its reasonable redox properties.

ELECTRONIC SPECTROSCOPY STUDIES OF A P2S5NH4OH TREATED GAS(100) SURFACE

Microscopic characteristics of the GaAs(100) surface treated with P2S5/NH4OH solution has been investigated by using Auger-electron spectroscopy (AES) and x-ray photoemission spectroscopy (XPS). AES reveals that only phosphorus and sulfur, but not oxygen, are contained in the interface between passivation film and GaAs substrate. Using XPS it is found that both Ga2O3 and As2O3 are removed from the GaAs surface by the P2S5/NH4OH treatment; instead, gallium sulfide and arsenic sulfide are formed. The passivation film results in a reduction of the density of states of the surface electrons and an improvement of the electronic and optical properties of the GaAs surface.

THE ADSORPTION OF O2 ON FESI SURFACES

The initial adsorption stages and the interaction of oxygen on FeSi surfaces have been studied as a function of exposure and annealing temperature using a variety of techniques including HREELS, AES, LEED, XPS and UPS. O2 was found to adsorb dissociatively on the FeSi surfaces at room temperature. The whole adsorption process can be divided into four stages. Heating promotes the oxidation of Si, and a thin SiO2 overlayer is formed on the surface when annealed at 450-degrees-C, while all FeOx species are reduced. Models for adsorbed atomic O on the FeSi(100) surface exposed to different oxygen exposures have been put forward to account for the observed experimental results.

PRELIMINARY-RESULTS OF GAAS SINGLE-CRYSTAL GROWTH UNDER HIGH GRAVITY CONDITIONS

GaAs single crystals have been grown under high gravity conditions, up to 9g0, by a recrystallization method with decreasing temperature. The impurity striations in GaAs grown under high gravity become weak and indistinct with smaller striation spacings. The dislocation density of surcharge-grown GaAs increases with increase of centrifugal force. The cathodoluminescence results also show worse perfection in the GaAs grown at high gravity than at normal earth gravity.

INTERFACIAL FORMATION PROCESS AND REACTIONS BETWEEN AU AND HYDROGENATED AMORPHOUS SI STUDIED BY XPS AND AES

Interfacial formation processes and reactions between Au and hydrogenated amorphous Si have been studied by photoemission spectroscopy and Auger electron spectroscopy. A three-dimensional growth of Au metal cluster occurs at initial formation of the Au/a-Si:H interface. When Au deposition exceeds a critical time, Au and Si begin interdiffusing and react to create an Au-Si alloy region. Annealing enhances interdiffusion and a Si-rich region exists on the topmost surface of Au films on a-Si:H.

Photoluminescence enhancement of (NH4)(2)S-x passivated InP surface by rapid thermal annealing

Photoluminescence enhancement of (NH4)(2)S-x passivated InP surface followed by rapid thermal annealing (RTA) has been investigated by using photoluminescence (PL), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), An increase in PL intensity of up to 10 times was observed after sulfur passivation and RTA treatment compared to unpassivated InP surface. XPS measurement results show that introduction of RTA process can enhance the sulfur remaining on the passivated surface to bond to indium but no evidence of S-P bond is noticeable. Passivation enhancement mechanism is discussed.

磁性半导体Gd_xSi_(1-x)的XPS研究

采用离子束技术,在n型硅基片上注入稀土元素钆,制备了磁性/非磁性p-n结.本文中使用的XPS对制备的样品进行测试,利用Origin 7.0提供的PFM工具进行研究,O1s束缚能介于金属氧化物和SiO_2中O1s的束缚能之间,Si2p的XPS谱分裂为两个峰,其中一个是单质Si的,另一个介于单质Si和硅化物之间,Gd4d的束缚能介于金属钆和氧化钆中的Gd4d之间,说明Gd_xSi_(1-x)形成了无定形结构.

非晶氮化硅薄膜退火前后微结构的XPS研究

于2010-11-23批量导入

气相和溶液多硫化物钝化InP表面的XPS和AFM研究

国家自然科学基金

氧离子束辅助激光淀积生长ZnO/Si的XPS研究

利用X射线光电子能谱深度剖析方法对ZnO/Si异质结构进行了分析。用该法可生长出正化学比的ZnO，不过生长的ZnO薄膜存在孔隙，工艺还有待进一步改进。

Ni?莫来石界面反应的XPS研究

国家自然科学基金