摘要:

A study of the electrolyte electroreflectance spectra of CuInS2grown by the traveling‐heater method has been made. The energy gaps and broadening parameters were studied by varying the composition of the samples. Our results show that the energy gaps are in the range of 1.52 to 1.53 eV and have band‐gap narrowing as the deviation from the stoichiometry increases, while the broadening parameters are in the range of 0.040 to 0.060 eV and found to be sensitive to the crystallization of the single crystal.

ISSN:0021-8979    

DOI:10.1063/1.337002

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

In this paper, we consider how oxidation in dry O2influences the point‐defect densities in silicon. By using relationships based on the continuity equations in the oxide and applying a proposed set of boundary conditions to the oxidizing Si‐SiO2system, we derive an analytic expression for the supersaturation of interstitials during oxidation. The analysis results in an expression having the experimentally observed sublinear dependence on oxidation rate without requiring any assumptions of nonlinearity. In addition, through observations of the dependence of the linear rate constant in the linear‐parabolic model of oxidation on ambient oxygen pressure, it is possible to predict how the interstitial supersaturation will vary with oxidation rate at a given temperature. A companion paper [J. Appl. Phys.59, 2551 (1986)] compares the predictions of the model with experimental results.

ISSN:0021-8979    

DOI:10.1063/1.337003

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

In the companion paper [J. Appl. Phys.59, 2541 (1986)], we developed a model based on a continuity equation approach for the supersaturation of interstitials during oxidation in dry O2. The analysis resulted in an expression having the experimentally observed sublinear dependence of oxidation rate without requiring any assumptions of nonlinearity. Through observations of the dependence of the linear rate constant at the linear‐parabolic model of oxidation on ambient oxygen pressure, predictions were made of how the interstitial supersaturation will vary with oxidation rate at a given temperature. In this paper, those predictions are compared to data for the enhanced diffusion of phosphorus in ⟨100⟩ silicon during oxidation at 900 and 1000 °C in both 100% O2and O2‐Ar mixtures as well as existing data for oxidation enchanced diffusion and stacking fault growth.

ISSN:0021-8979    

DOI:10.1063/1.337004

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Using charged particle activation analysis, oxygen concentration in silicon crystals heavily doped with antimony has been shown to be considerably lower than in undoped crystals grown under otherwise the same conditions. The difficulty of oxygen precipitation in these doped crystals is therefore due to the lowered oxygen concentration and also to the difference in the dopant effect on precipitate formation.

ISSN:0021-8979    

DOI:10.1063/1.337005

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A design of solar cells with reduced junction area on the cell surface is investigated for reduction of saturation current and increase in open‐circuit voltage. Equidiameter dot junctions distributed across the surface of the cell offer an efficient alternative, with variations in dot diameter and in the spacing between dots giving the required variations in the ratio of junction area to total surface area. A simplified analysis for short‐circuit current and other cell parameters, which enables cell design optimization, is presented. Experimental solar‐cell performance results, as functions of different area ratios, are presented and compared with the model. It is shown that saturation current reduction is possible for achieving efficiencies as high as 18% in flat‐plate terrestrial applications.

ISSN:0021-8979    

DOI:10.1063/1.337006

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The spatial variation of minority‐carrier diffusion length in the vicinity of a boundary surface in monocrystalline and semicrystalline silicon solar cells has been measured by the scanned monochromatic light beam induced current (MBIC) technique with a very small spot size (2&mgr;m in diameter) and 750–1050‐nm‐long wavelength light beam. The technique we developed uses a short‐arc xenon lamp source with line spectra. It was found that most of the grain boundaries in cast semicrystalline silicon materials were accompanied with crystal imperfections along them, and the effect of a boundary surface extended beyond the distance of a minority‐carrier diffusion length. Furthermore, the effective minority‐carrier diffusion length due to crystal imperfections in the vicinity of the grain boundary was estimated and it was indicated that the grain boundary where the crystal imperfections were concentrated could be characterized using the concept of the effective influence width of grain boundary.

ISSN:0021-8979    

DOI:10.1063/1.337049

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The propagation characteristics of millimeter waves in an H guide loaded with yttrium iron garnet films are investigated. A perturbation theory is used for evaluating the dispersion curve. Theoretical results are confirmed by experiments carried out in the millimeter wave frequency range 40–50 GHz using yttrium iron garnet films. Dispersion characteristics for a laminated structure of yttrium iron garnet films are also examined. The gyromagnetic resonance behavior with a higher quality factor is observed when the dielectric slab is loaded on both sides with yttrium iron garnet films.

ISSN:0021-8979    

DOI:10.1063/1.337007

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

First‐, second‐, and third‐order gradiometers used in detecting biomagnetic signals are analyzed as spatial filters. Their transfer functions independent of the source to be measured are presented and both the magnitude and phase characteristics of the transfer functions are analyzed. The distortion introduced by the gradiometer can be estimated from these characteristics. In order to treat the signal in that approach, the spatial Fourier transform of a magnetic signal produced by a current dipole at a given distance is discussed.

ISSN:0021-8979    

DOI:10.1063/1.337008

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Results on electrical conductivity in keV‐electron‐irradiated hydrogenated amorphous silicon are presented. Increases in both the conductivity activation energy and the resistivity are observed in irradiated samples. Some possible uses of this effect are discussed.

ISSN:0021-8979    

DOI:10.1063/1.337009

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Generation lifetime and surface generation velocity were measured by capacitance transient analysis of metal‐oxide‐semiconductor capacitors to study the effect of high‐energy neutron irradiation in the fluence range 1012–1014cm−2. Thirty‐minute isochronal anneals show that the generation lifetime and surface generation velocity recover their preirradiation values at 470 °C, which is close to the temperature for annealing of recombination lifetime decreases produced by electron irradiation. The relatively low value of annealing temperature for the recovery of lifetime after neutron irradiation is in sharp contrast with the improved thermal stability of lifetime effects produced by ion implantation into silicon when compared to the case of electron irradiation.

ISSN:0021-8979    

DOI:10.1063/1.337010

出版商:AIP    

年代:1986

数据来源: AIP