摘要:

The photoplastic effect is observed in anthracene single crystals under illumination with near‐ultraviolet light. The overall features of the action spectrum of hardening bear a close resemblance to the absorption spectrum. The maximum hardening due to illumination reaches as much as 10% of yield stress at 120 W/m2.

ISSN:0003-6951    

DOI:10.1063/1.92440

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Simple techniques for doubling the spatial frequency of surface‐relief gratings are demonstrated. Grating periods as small as 750 A˚ have been produced and further subdivision appears possible.

ISSN:0003-6951    

DOI:10.1063/1.92441

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Reactions between Si and thin films of rare‐earth metals (Gd, Dy, Ho, Er, plus Y and La) in the temperature range of 275–900 °C have been studied by using x‐ray diffraction and ion backscattering spectrometry. The disilicides of these metals are apparently the first phase to form, forming rapidly within a narrow temperature range (325–400 °C), and are stable up to 900 °C. The growth does not follow a layered growth mode.

ISSN:0003-6951    

DOI:10.1063/1.92442

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Solar cells which show a field‐dependent collection efficiency in the current saturation range must exhibit a field‐dependent carrier redistribution over localized states within the junction. Such redistribution may be caused by″field quenching″which is a well‐known effect in photoconductive CdS, providing for field saturation and consequently causing the short‐circuit current to saturate before the emitter limit is reached.

ISSN:0003-6951    

DOI:10.1063/1.92443

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A study was performed to establish the origin and nature of background compensating impurities in undoped ZnSe layers grown by liquid phase epitaxy on ZnSe substrate wafers in a low‐contamination‐level environment. The width of bound exciton lines in low‐temperature photoluminescence spectra was used to define the quality of the material, and the energy of the lines was used to identify these low‐level impurities. The sharpest spectra occurred in layers grown rapidly on a previously grown buffer layer indicating the importance of impurity outdiffusion from the substrate into the growing layer. The sharpness of these bound exciton lines indicates that the total concentration of electrically active impurities (NA+ND) is <1017/cc, an estimate which is confirmed by mass spectroscopy.

ISSN:0003-6951    

DOI:10.1063/1.92444

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Epitaxial GaxIn1−xAsyP1−ylayers several microns thick have been grown on (100) InP substrates by ramp cooling. Using high‐resolution double x‐ray diffractometry, the profiles obtained from such layers could be resolved into several peaks. Chemical thinning of the layers allowed these peaks to be attributed to successive sublayers having slightly different perpendicular lattice parameters, the lattice parameter within each sublayer being constant.

ISSN:0003-6951    

DOI:10.1063/1.92445

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Auger peaks of 82‐eV Si and 381‐eV N have been used to study the preferential enrichment of one component of Si3N4after sequential sputtering with 0.5‐ and 2.0‐keV Ar+and He+ions. The results clearly indicate that the element enriched at the surface, due to sputtering, depends on the mass of the impinging ion, and the magnitude of the enrichment depends on the energy of the ion. For example, N was enriched by Ar+, while Si was enriched by He+bombardment. These results are explained by considering direct knockoff and energy transfer processes in sputtering.

ISSN:0003-6951    

DOI:10.1063/1.92446

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The silicon‐on‐sapphire (SOS) interface has been studied using a new approach based on the use of the mechanically thinned sapphire as a metal insulator semiconductor gate insulator. A final sapphire thickness of 5 mm has been achieved. 1‐MHz capacitance‐voltage profiles exhibit a pronounced hysteresis, which is investigated using electrical and thermal stress, time‐resolved capacitance and laser‐induced photocapacitance. A native polarizable interfacial layer in SOS is shown to be the possible mechanism for the observed hysteresis. An interface model including a polarizable layer (equivalent to a reduced charge of the order of 1011e/cm2), interface states (at midgap 1×1012states/cm2/eV), and fixed charges is presented.

ISSN:0003-6951    

DOI:10.1063/1.92447

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Quantization of the Hall resistance of the two‐dimensional electron gas in GaAs‐AlxGa1−xAs heterostructures is observed at 4.2 K and at magnetic fields as low as 4.2 T. This demonstrates its practical use as a primary resistance standard.

ISSN:0003-6951    

DOI:10.1063/1.92408

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Electric charge in the GaAs native oxide formed by anodic oxidation and by plasma oxidation was successfully characterized utilizing contact potential difference measurements. Negative electric charge as high as 1012q/cm2was found in all oxide layers independent of their thickness. At room temperature this charge can be effectively screened out by absorption of polar molecules (organic solvents) which thermally desorb at 70 °C. Higher temperature annealing (70–180 °C) irreversibly reduces the charge in oxide by over an order of magnitude. It is shown that the oxide charge reflects the internal electric polarization created during the oxidation process.

ISSN:0003-6951    

DOI:10.1063/1.92409

出版商:AIP    

年代:1981

数据来源: AIP