Relationship between the Local Vibration Mode Characteristics and the Charge State of Carbon Acceptor in GaAs

The local vibration mode(LVM)of carbon acceptor in GaAs is studied by measuring directly the change in LVM absorption with a NIC-170 SX FT-IR spectrometer.The change in the charge state of carbon acceptor and the temperature dependence of the LVM absorption were investigated also.The contents of the impurities other than carbon were estimated by secondary ion mass spectrometry.It is observed that the frequency,the spectral form and the integrated absorption of the LVM are not affected by the change in charge state of car- bon acceptor.

Sideband Absorption and its Effects on Temperature Dependence of Local Vibrational Mode Main Absorption Band for Carbon Acceptor in Gallium Arsenide

The local vibrational mode (LVM) optical absorption band of carbon acceptor was investigated carefully. Because of the appearance of a sideband on the low energy side of the LVM main absorption band, it is found that the measured value of the integrated area for the main absorption band is sensitive to the choice of integration baseline wavenumber range (BWR). This is the main cause that the experimental results from different investigators show a wide spread for the temperature dependence of the integrated area. The origin of the sideband is also discussed.

Effects on dynamic characters of antenna structures in satellite induced by disordered parameters

A simplified dynamic model of a dish antenna in satellite is established in this article.The modelcan be easily used to analyze the dynamic behaviour of the antenna structure.In terms of the simplifiedmodel,effects on dynamic characters due to the disorder of parameters are investigated in details.Thefrequencies calculated by the simplified model accord with those computed by ANSYS.Based on the modeshapes of disordered and perfect structure,the influence law and varying trend of dynamic characters ofantenna structures in satellites produced by stiffness and mass of antenna ribs,stiffness of antenna mem-branes and angles between adjacent ribs,are obtained.The analyses in the paper indicate that the effectsby disordered parameters can not be ignored in the dynamic analysis of such structures.

C-H complex defects and their influence in ZnO single crystal

Infrared absorption local vibration mode（LVM） spectroscopy is used to study hydrogen related defects in n-type ZnO single crystal grown by a closed chemical vapor transport（CVT） method under Zn-rich growth conditions, in which carbon is used as a transport agent. Two C-H complex related absorption peaks at 2850 cm-1and 2919 cm-1 are detected in the sample. The formation of the C-H complex implies an effect of carbon donor passivation and formation suppression of H donor in ZnO. The influence of the complex defects on the electrical property of the CVT-ZnO is discussed based on Hall measurement results and residual impurity analysis.

Stability and vibrational properties of the hydrogen atom for p-type AlN doped with group-Ⅱ:a first-principles study

The stability and local vibrational mode（LVM） of hydrogen related p-type AlN have been studied by firstprinciples calculations based on density functional theory.The stable and metastable microscopic geometries of group-Ⅱ（Be,Mg,Ca,Sr,Ba）-H complexes have been investigated.The calculated results indicate that BC_（‖） is the most stable configuration for isolated interstitial H~＋ and Be-H complexes,while it is AB_（n,⊥） for Mg-H,Ca-H,Sr-H and Ba-H complexes.Moreover,the vibrational frequencies and the values of k and ｜α｜ for the H atom with LVM are calculated. Here,the values of k and ｜α｜ are used to describe the parameters of the harmonic and anharmonic contributions,respectively. The calculated results indicate that the larger the size of the doped ion is,the shorter the N-H bond length is,and the larger the potential energy,the vibrational frequencies,the values of k and ｜α｜ are.This implies that the size of the doped ion has an important influence on the vibrational properties of H.