摘要:

We employ the technique of deep‐level transient spectroscopy to study a series of rapidly degraded GaAs0.6P0.4LED’s. We observe a dramatic increase in the density of defects, two of which appear to be effective recombination centers. The cross‐section measurements for these centers are equipment limited, but even these values limit the nonradiative minority‐carrier lifetime to less than 20 ns.

ISSN:0021-8979    

DOI:10.1063/1.325140

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A degraded Ga1−xAlxAs double‐heterostructure injection cw laser diode with a lifetime of 1070 h was examined in cross section by TEM. The device contains defects whose contrast is identical to that produced by coherent or partially coherent precipitates and/or by prismatic dislocation loops. They have not previously been observed either in undegraded Ge‐ or Sn‐doped material or in devices degraded by DLD formation. These defects were observed in the topp(Ge) ‐GaAs layer as well as in thep(Ge) ‐Ga1−xAlxAs layer adjacent to it. There is a tendency for these defects to decorate the interface between these two layers as well as the interface between the active region and thep(Ge) ‐Ga1−xAlxAs layer. Furthermore, these defects seem to cluster in regions adjacent and above these two interfaces. These defects have not, however, been observed in the active, then‐ (Sn) ‐Ga1−xAlxAs, and then‐GaAs substrate regions.

ISSN:0021-8979    

DOI:10.1063/1.325141

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Lead silicate glass sputtered onto GaAs‐AlGaAs injection lasers facets can yield optical coatings with near‐perfect linear‐expansion matching or refractive‐index matching by adjusting the PbO : SiO2ratio. Half‐wave coatings increase the lasing threshold by less than 5&percent;, while quarter‐wave coatings allow a large increase in power output for less than a 30&percent; increase in lasing threshold.

ISSN:0021-8979    

DOI:10.1063/1.325142

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The emission wavelengths at 16 &mgr;m of a two‐photon‐excited ammonia laser has been measured with improved accuracy. The measurement technique involves accurate calibration of the monochromator using well‐known spectral lines and boxcar amplifiers to measure the total laser energy per laser pulse and the energy transmitted through the monochromator.

ISSN:0021-8979    

DOI:10.1063/1.325143

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Continuous‐wave laser operation at 300 °K at 941 and 1059 nm has beeen demonstrated using Nd : CAMGAR. Discrimination against the 1059‐nm line required only tuned dielectric mirrors because of the strong 941‐nm fluorescence. Gain and loss coefficients at 1059 nm were determined.

ISSN:0021-8979    

DOI:10.1063/1.325144

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The propagation and attenuation characteristics of electromagnetic waves through a waveguide filled with moving isotropic lossy homogeneous (TEmnmodes), as well as inhomogeneous (TEm0modes) plasma for the appropriate modes, have been theoretically studied. The expressions for the propagation and attenuation constants for TE and TM modes are found to be the same and dependent on waveguide dimension, plasma parameters, and drift velocity. The propagation characteristics near the waveguide walls are seen to be similar to the free‐space waveguide. For special cases, the effect of the inhomogeneity of the plasma medium has also been discussed. The power flow and field components existing in waveguides are also discussed in brief.

ISSN:0021-8979    

DOI:10.1063/1.325145

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Dual implants of C+and Ga+ions in GaAs have been investigated by sheet‐resistivity and Hall‐effect measurements. Efficient doping has been achieved by dual implantation, even at an annealing temperature of 700 °C. Analysis of electrical profiles indicates that the concentration of substitutional atoms in As sites is less than the implanted dose; the remaining C atoms are believed to out‐diffuse through encapsulation during annealing. Although the doping efficiency for the dual implants is higher than that of the single implants, the effective compensation ratio is about the same, which suggests that ’’self‐compensation’’ may be the predominant mechanism in the implanted samples.

ISSN:0021-8979    

DOI:10.1063/1.325146

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Recent data on subgrain size and spacing gradients in the Cu‐Ni system allow a more critical examination of a technique currently used to obtain the composition profiles of small diffusion zones. These data support the assumption that the broadening from individual subgrains need not include a spacing gradient term when volume diffusion is predominant. However, care should be taken in the interpretation of the earliest stage of diffusion where grain boundaries, surface, and other defects may introduce large spacing gradients.

ISSN:0021-8979    

DOI:10.1063/1.325147

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

HCl addition to an oxidiing ambient during thermal oxidation of silicon can prevent the generation of oxidation‐induced stacking faults in the crystal during the subsequent standard thermal‐oxidation cycles. The gettering action of stacking‐fault nuclei from the surface regions of the silicon wafers is induced under appropriate HCl oxidation conditions (temperatures, times, and HCl concentrations). Conditions for an undesirable etching of the silicon surface are also presented. These two phenomena presumably occur when certain concentrations of a chlorine species are incorporated near the silicon–silicon dioxide interface.

ISSN:0021-8979    

DOI:10.1063/1.325148

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Minority‐carrier lifetimes in silicon crystals measured by surface photovoltage and photoconductive decay methods have been compared. The results from both measurements are in reasonable agreement provided that the thickness of the sample for surface photovoltage measurements is at least twice the diffusion length.

ISSN:0021-8979    

DOI:10.1063/1.325149

出版商:AIP    

年代:1978

数据来源: AIP