Phonon heat transport in silicon nanowires

Thermal conductivity of silicon and porous silicon nanowires based on the equation of phonon radiative transport is theoretically evaluated. The thermal conductivities of silicon nanowires with square cross-sections are found to match molecular dynamics simulation results reasonably well. It is shown that the results of meso-porous silicon nanowires are about two orders of magnitude lower than that of silicon nanowires in a wide range of temperature (50 K-300 K). Received 24 April 2001 and Received in final form 23 December 2001     

Plasma reflection in gallium arsenide

Procedures recently proposed for determining electrophysical parameters of highly doped semiconductors from the IR reflection spectra are analyzed. The case of n-type GaAs is discussed. Optical and Hall measurements have been carried out for a few samples, and it has been found that the electron density determined from the optical measurements is in good agreement with the Hall values, while the mobilities may differ significantly. It is concluded that mechanical polishing causes problems.Translated from Izvestiya VUZ. Fizika, No. 10, pp. 65–69, October, 1969.     

Phonon dispersion in aluminium arsenide and antimonide

The phonon dispersion curves for aluminium arsenide and antimonide have been investigated by using a deformation bond approximation model. The results obtained from this model are compared with the experimental values wherever it is available. Since there is no complete experimental phonon dispersion curves for AlAs, we could not compare our calculated results, but the results of AlSb have been compared with the inelastic neutron scattering measurements at 15 K. However, we compare the phonon frequencies of AlAs and AlSb at critical points of the Brillouin zone obtained by our calculations and Raman spectroscopy measurements. This model predicts the phonon modes satisfactorily in all the symmetry directions of the Brillouin zone (BZ). The spectrum has similar features as observed in other III–V compound semiconductors.     

Heat-stimulated currents in semi-insulating gallium arsenide

The energy spectrum of charge carrier traps of semi-insulating n-type gallium arsenide has been investigated by the method of heat-stimulated currents and the parameters characterizing these traps have been estimated. Trap acceptor levels with energies 0.37, 0.41 and 0.17, 0.28, 0.32, 0.34, 0.38, 0.40 eV have been found for samples with the specific resistivity 2.7 · 10⁷ and 1.6 · 10⁸ · cm, respectively. The results obtained are well explained within the framework of the theory of a compensated semiconductor.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 22–26, November, 1971.The authors are grateful to A. P. Vyatkin, V. G. Voevodin, and E. V. Kozeev for kindly providing the gallium arsenide crystals and stimulating the research.     

Thermal oxidation of gallium arsenide

The experimental results of this study of the thermal oxidation of GaAs under atmospheric conditions and in dry oxygen over a temperature range of 400–530C are presented. It is shown that for temperatures in the range of 400–450C the oxide layers are formed according to a parabolic law while for temperatures in the range of 480–530C they are formed according to a linear law. An interesting dependence of the reflectivity of GaAs with an oxide layer on the thickness of this layer during the initial stage of the oxidation process is described, giving evidence of the complex structure of the layer formed.     

Residual lattice absorption in gallium arsenide

The residual lattice absorption of GaAs in the three and four phonon regime is measured over a range of temperatures. The spectra reveal persistent structural features which are interpreted theoretically in terms of phonon density of states effects.     

Oscillatory photoconductivity of gallium arsenide

The photoconductivity of GaAs in the energy range 1.5 –1.8 eV at 4.2 K exhibits two types of quantum oscillations: Landau oscillations for epitaxial material in high magnetic fields or LO phonon oscillations for high resistivity material. The purity and surface treatment of the samples seem to determine the type of oscillations observed.     

Ion doping of gallium arsenide

Conclusion The survey presented shows that despite the intensive study of the physical problems of ion implantation in GaAs, there is still a number of questions to investigate. Among them are: The role of anomalous diffusion and channeling in the formation of concentration profiles, the anomalous diffusion mechanism, the influence of radiation defects and residual impurities as well as the form of the coating, the interaction between impurities and defects under ion implantation, and the identification of radiation defects, A further study of the above-mentioned questions will permit extension of the application of the ion implantation method to obtain GaAs semiconductor instruments and realization of still unused possibilities of this powerful method of modern semiconductor technology.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 76–90, January, 1980.     

半绝缘砷化镓单晶中碳微区分布的研究

通过AB腐蚀（由Abrahams和Buiocchi发明的腐蚀方法，简称AB腐蚀）、KOH腐蚀，经金相显微镜观察、透射电子显微镜能谱分析、电子探针x射线微区分析，对液封直拉法生长的非掺 半绝缘砷化镓单晶中碳的微区分布进行了分析研究.实验结果表明，碳的微区分布受单晶中 高密度位错网络结构的影响.高密度位错区，位错形成较小的胞状结构，且胞内不存在孤立 位错，碳在单个胞内呈U型分布；较低密度位错区，胞状结构直径较大，且胞内存在孤立位 错，碳在单个胞内呈W型分布. 关键词： 半绝缘砷化镓 胞状位错 碳受主     

Optical properties of laser-type gallium arsenide

Measurements of the optical properties of laser-type Ga As indicate a peak in the refractive index at the absorption edge frequency. The magnitude of the peak decreases as the doping levels are increased and the slope of the absorption edge decreases.