摘要:

18–19‐MeV He++axial channeling in Si has been measured by the conventional single‐alignment method. In the backscattering spectrum, a shift of the resonant nuclear scattering peak to high‐energy side was observed when an axial channeling occurred. Moreover, the peak shift became maximal for about critical‐angle incidence of He++. These are direct evidences that the high‐energy‐loss fraction of channeled ions is considerably responsible for forming a backscattering spectrum.

ISSN:0021-8979    

DOI:10.1063/1.329246

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Epilayers of (Alx,Ga1−x)As(0.03<x<0.38) up to 1.4 mm thick were grown for the first time by Peltier‐induced liquid phase epitaxy (LPE) (electro epitaxy). The epilayers were analyzed with photoluminescence microanalysis and showed thick segments (up to 600 &mgr;m) of extremely uniform aluminum composition. Compositionally graded regions varied from lowXSALASto highXSALASin moving from the bottom to the top of the layer. The growth was performed at constant furnace temperature (T = 800 °C), with a small solution volume (15 g) and with an electric current of 10 A/cm2as the sole driving force for the growth. The compatibility of this technique with the growth of complex multilayer structures was demonstrated.

ISSN:0021-8979    

DOI:10.1063/1.329247

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Linear morphological features which are readily revealed using Nomarski interference contrast microscopy have been observed on the surfaces of GaxAl1−xAs epitaxial layers grown by liquid phase epitaxy LPE on GaAs substrates at 950 °C. These features are introduced along one <110≳ direction in the (001) growth surface only. Annealing at the growth temperature produces a similar set of features in the perpendicular <110≳ direction. Photoluminescence topographs reveal dark lines in the substrates that are directed parallel to the sets of surface features in both annealed and unannealed crystals.

ISSN:0021-8979    

DOI:10.1063/1.329248

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

In an attempt to clarify the controversial views about the general validity of the rather frequently and successfully used critical state mode, we consider an explicit formulation of this model and present a careful analysis of the boundaries of the regions where the fieldBis zero. As a result, it seems that the arguments recently published that call into question the general validity of this mode are not acceptable.

ISSN:0021-8979    

DOI:10.1063/1.329249

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The comment by Baixerasetal. [J. Appl. Phys. 52, 4330 (1981)] on the recent paper by Migliori [J. Appl. Phys. 51, 3439 (1980)] utilizes counterexamples not consistent with Migliori’s premise. Baixerasetal. also fail to support their contention that in two dimensions it is possible, if more difficult, to solve a general critical state model with boundary conditions.

ISSN:0021-8979    

DOI:10.1063/1.329250

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We have found thatB(the square of the gradient of (&agr;h&slash;&ohgr;)1/2versus h&slash;&ohgr; plot) is dependent on the preparation conditions ofa‐Si:H films and has a distinct correlation with photoconductivity.Bincludes information on the tail states and the band edge of extended states ofa‐Si:H.Bis proposed as one of important characterization parameters fora‐Si:H as well as photoconductivity.

ISSN:0021-8979    

DOI:10.1063/1.329267

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Measurements have been made of the Raman spectra of silicon implanted with either11B or10B and subsequently thermally annealed. These measurements, taken with an argon‐ion laser operating at 514.5 nm and at room temperature, revealed the presence of an intrinsic two‐phonon combination band underlying the11B local mode. The coincidence of these two spectral features complicates the analysis of the annealing process as diagnosed on the basis of the Raman spectrum. The use of the10B isotope, and its spectra, minimizes ambiguities in interpretation of the spectra of ion‐implanted silicon. A reexamination of the earlier annealing studies of Engstrom and Bates is suggested on the basis of the present results.

ISSN:0021-8979    

DOI:10.1063/1.329251

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Because separate experiments have shown that our samples were well annealed, we disagree with the conculsion of Formanetal. [J. Appl. Phys. 52, 4337 (1981)], that accounting for the silicon optic mode lineshape requires inclusion of the effect of incomplete annealing.

ISSN:0021-8979    

DOI:10.1063/1.329252

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Transmission electron microscopy and the cathodoluminescence mode in the scanning electron microscope have been used to study indented MgO single crystals and to relate luminescence emission and defect structure. Color images of cathodoluminescence indentation rosette have been also obtained. Marked differences in the emission and the defect structure in different areas of indentation have been found and in particular a high density of defects have been observed in the center of indentation including some defects which seem to be characteristic of this region.

ISSN:0021-8979    

DOI:10.1063/1.329264

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Optimum design for a window layer thickness of GaAlAs‐GaAs heteroface solar cell has been performed regarding the effect of reflection loss. It is shown that the GaAlAs layer thickness greatly affects the reflection characteristics of the cell and that there is an optimum thickness for the GaAlAs layer. Thus the GaAlAs layer thickness must be designed so as to minimize the reflection loss, as well as the absorption loss by the window. Optimum thickness for the GaAlAs layer is about 0.03 &mgr;m, and the power reflection loss for the cell with optimized double antireflection (AR) coatings is as low as 1.09 % for AM0 solar radiation.

ISSN:0021-8979    

DOI:10.1063/1.329265

出版商:AIP    

年代:1981

数据来源: AIP