摘要:

Initial stage of the C49–TiSi2formation was investigated at 530 °C and at a rate of 10 °C/m using transmission electron microscopy. Morphological studies reveal that the C49 phase first separately nucleates at the interface between amorphous silicide and crystalline silicon, then followed by simultaneous lateral and vertical growth. The growth proceeds very fast until the formation of a continuous layer of C49–TiSi2. Local chemical analysis shows that the composition range of the amorphous silicide is narrowed due to the C49 formation. For isothermal annealing, a linear density of the C49 nuclei is about 6.7×10−3/A˚, and remains the same upon prolonged annealing. In the case of annealing at 10 °C/m, the linear density depends on temperature, reaching a maximum of 7.2×10−3/A˚ at around 575 °C.

ISSN:0021-8979    

DOI:10.1063/1.354602

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Schottky barrier diodes have been fabricated using poly(3‐hexylthiophene)(P3HT) as the semiconductor and indium as the metal. P3HT was doped with FeCl3at room temperature to form ap‐type semiconductor. The Schottky junctions of In on FeCl3‐doped P3HT using pressure contact exhibit rectification ratios ranging from 104:1 to 106:1 at a bias of ±1 V.

ISSN:0021-8979    

DOI:10.1063/1.355319

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Nd:YAG‐laser‐induced evaporation of particulates formed in an Ar‐CCl2F2rf plasma and the subsequent discharge in the vapor have been investigatedinsituby means of optical emission spectroscopy. The estimated threshold for discharge formation is 5×106W/cm2. The maximum laser‐induced emission intensity is observed when the laser is operated in the long‐pulse mode (about 200 &mgr;s pulse duration) at the fundamental frequency. The wavelength integrated intensity of this continuum emission has been compared with light scattering intensity at the same laser energy. It has been found that the laser‐induced emission intensity can be more than ten times higher than the scattering intensity, especially for particulates with a diameter much smaller than the wavelength of the laser. Therefore, this effect provides a sensitive particulate detection method.

ISSN:0021-8979    

DOI:10.1063/1.354603

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Anomalous optogalvanic line shapes were observed in a commercial hollow cathode lamp containing argon buffer gas. Deviations from Gaussian line shapes were particularly strong for transitions originating from the3P2metastable level of argon. The anomalous line shapes can be described reasonably well by the assumption that two regions in the discharge are excited simultaneously, each giving rise to a purely Gaussian line shape, but with different polarities, amplitudes, and linewidths.

ISSN:0021-8979    

DOI:10.1063/1.354604

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The nonlinear rupture problem of a thin power‐law liquid film on a horizontal plane is studied. A nonlinear evolution equation is first derived forh(x,t), the film thickness, and then it is solved by numerical methods. The results reveal that the rupture time of the film decreases with decreasing the magnitude of the power‐law exponent,n.

ISSN:0021-8979    

DOI:10.1063/1.354605

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

It is shown that a combination of low‐temperature photoluminescence and luminescence excitation spectroscopies together with appropriate modelization can provide the precise information needed for a thorough control of interdiffusion in quantum well structures. A fit of observed and calculated transition energies up to five energy levels, using the interdiffusion length as a unique parameter, is considered. The potentiality of this procedure to fully characterize the interdiffusion process is illustrated by considering the examples of lightly and heavily intermixed GaAs‐AlGaAs multiquantum wells.

ISSN:0021-8979    

DOI:10.1063/1.354606

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The gain saturation coefficients of tensile‐strained, lattice‐matched, and compressive‐strained InGaAs/InGaAsP quantum‐well lasers (QWLs) are calculated from intrasubband relaxation times. The intrasubband relaxation times are in turn obtained within the random‐phase approximation including carrier–carrier and carrier–polar‐optical phonon interactions at room temperature. The effects of strain on the band structures are included by taking into account the strain‐dependent coupling among heavy‐hole, light‐hole, and spin‐orbit split‐off subbands on the basis of the multiband effective‐mass theory. It is demonstrated that the gain saturation coefficient in tensile‐strained QWLs is less sensitive to the amount of strain than in compressive‐strained QWLs where it markedly increases with strain.

ISSN:0021-8979    

DOI:10.1063/1.354607

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Microstructural evaluation of thick (In,Mn)As epitaxial films grown by molecular‐beam epitaxy on InAs/GaAs(100) substrates is carried out by transmission electron microscopy (TEM). Films grown at the substrate temperature ofTs=300 °C show the inclusion of MnAs crystallites in the zinc‐blende host matrix, in which two types of crystallite morphologies, rod and approximately round shapes, are identified. In contrast, the MnAs crystallites are not observed in films grown atTs=200 °C, and TEM studies confirm that the films are primarily of zinc‐blende structure. Microstructural defects in the films are also discussed to assess the quality of epitaxy.

ISSN:0021-8979    

DOI:10.1063/1.354608

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A photoluminescence study has been made on an oxygen‐containing Si fine structure fabricated by a gas evaporation technique. Transmission electron micrographs have shown that the fine structure is composed of nonspherical particles aggregated together in chain‐like or cluster‐like structures. The luminescence from the samples after oxidation treatment is bright blue as viewed with the naked eye, the spectra having a peak at about 470 nm or shorter wavelength. A peculiar temperature dependence of the emission peak indicates that the emission is strongly correlated with some structural change in the fine structure.  

ISSN:0021-8979    

DOI:10.1063/1.354609

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The elastic strain limit of polycrystalline mixed AgClxBr1−xfibers was studied. These fibers are useful as flexible infrared optical fibers, and the elastic bending regime is preferred for applications which require many bending cycles. The experimental method was based on the spring‐back upon releasing a stressed material, and used specifically calculated expressions. Elastic strain limit values are in the range of 0.15%–0.4%. They depend on composition going through a maximum at around the AgCl0.5Br0.5composition. The dependence on composition is explained by a theoretical model, which is based on a solid‐solution internal stress field, and uses material constants.

ISSN:0021-8979    

DOI:10.1063/1.354610

出版商:AIP    

年代:1993

数据来源: AIP