摘要:

The anomalous photovoltaic effect in ferroelectrics is capable of producing imagewise distributions of voltages sufficiently high to allow for conventional xerographic development. The electric latent image will persist for long periods of time. The kinetics of the buildup of photovoltage has been studied on undoped LiNbO3and shown to conform to theoretical expectations: the saturation values of the field strongly depend on light intensity.

ISSN:0003-6951    

DOI:10.1063/1.90319

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

SAW resonators have been fabricated from reflection strip arrays of ZnO films on borosilicate glass substrates by rf sputtering and standard photolithographic processing. UnloadedQvalues were nearly 1000 and a linear temperature coefficient of about −10 ppm/°C was obtained when operated at a frequency of 100 MHz. AchievableQvalues for ZnO/glass SAW resonators at this frequency are discussed.

ISSN:0003-6951    

DOI:10.1063/1.90320

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A behavior typical of amorphous solids has been observed at very low temperatures for a layer obtained by ion implanting a quartz substrate. A surface‐acoustic‐wave velocity variation has been measured between 0.9 and 6 K for crystalline and implanted quartz by building a 960‐MHz delay line oscillator. The quartz substrate was implanted with helium ions at 95 keV. Over a limited temperature range, the velocity on the implanted surface is proportional to the logarithm of the temperature according to the off‐diagonal interaction between the acoustic wave and a broad distribution of two level defects. An increase of the proportionality coefficient is produced by an annealing at 567 °C and it seems related to a decrease of the specific mass. Moreover, the defect density of states is smaller than that of vitreous silica.

ISSN:0003-6951    

DOI:10.1063/1.90321

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The energy loss per unit path length for a charged particle incident on a spatially uniform isothermal Maxwellian plasma is a function of the temperature and density of the medium. Within this model the temperature and compression &rgr;&Dgr;rof the tamper of a laser‐driven microshell target can be accurately determined, in the absence of electrostatic acceleration, by the simultaneous measurement of the energy loss from 3.52‐MeV &agr; particles from D‐T reactions and 3.02‐MeV protons from D‐D reactions.

ISSN:0003-6951    

DOI:10.1063/1.90322

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have investigated the electron loss spectra of precipitates formed in annealed silicon crystals. The precipitates, as well as residue of the precipitates in precipitation sites, uniquely give rise to an energy loss at 532 eV. The energy loss is due to the excitation of oxygen 1selectrons. The precipitates are therefore identified as silicon oxide.

ISSN:0003-6951    

DOI:10.1063/1.90323

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Vapor‐deposited amorphous silicon films of 4000 A˚ thickness have been epitaxially crystallized on (100) silicon substrates by pulsed Nd : YAG laser radiation of 125‐nsec duration at power levels of 90–120 MW/cm2. The epitaxial layers were found to be defect free when examined by transmission electron microscopy and Rutherford backscattering. Patterned arrays of epitaxial crystal were produced by overlapping individual 39‐&mgr;m laser pulse spots.

ISSN:0003-6951    

DOI:10.1063/1.90324

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Numerical simulations of exploded wire plasmas have been conducted using a two‐dimensional (r‐z) magnetohydrodynamic computer code for several experimental configurations. Recent results with an aluminium wire showing the development of the nonlinear sausage instability are presented. Short‐wavelength modes are observed to grow and saturate initially, while longer wavelengths evolve later through nonlinear processes, particularly magnetic field diffusion. This behavior, as well as predicted energy output, appears to be consistent with experiment.

ISSN:0003-6951    

DOI:10.1063/1.90308

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Amorphous Fe‐B ribbons with 72‐88a/oFe were prepared by melt‐spinning. The inception of crystallization and the growth of crystals was determined by differential scanning calorimetry. The activation energy, &Dgr;E, and the pre‐exponential constant,A, for both the inception of crystallization and the peak in the crystallization exotherm are independent of composition from 72‐82a/oFe. &Dgr;EandAsteadily decline as the Fe content is increased from 82 to 88a/oFe. The concurrence of the &Dgr;EandAvalues for the inception of crystallization and for the peak in the crystallization exotherm suggests that the same diffusion mechanism is controlling the kinetics in both periods. This compositional dependence of constants in the Arrhenius relation is attributed to decreased filling of holes by B in the Bernal‐like structure as the Fe content increases.

ISSN:0003-6951    

DOI:10.1063/1.90309

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We demonstrate that a single short pulse of electron irradiation of appropriate energy is capable of recrystallizing epitaxially an amorphous Ge layer deposited on either ⟨100⟩ or ⟨111⟩ Si single‐crystal substrate. The primary defects observed in the ⟨100⟩ case were dislocations, whereas stacking faults were observed in ⟨111⟩ samples.

ISSN:0003-6951    

DOI:10.1063/1.90310

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The design and fabrication of high‐efficiencyp+‐n‐n+back‐surface‐field silicon solar cells are described. The fabrication process has been developed to yield maximum attainable carrier lifetimes (∼0.7 msec) in the base region of the cell, thereby allowing the backn‐n+junction to effectively enhance the cell performance. A surprising conclusion drawn from a study of the device physics supporting the experimental development of the cell is that the front‐surface recombination velocity controls the recombination in the emitter. That is, the bulkp+emitter is ’’transparent’’ to minority‐carrier (electron) flow. The recognition of the significance of the front silicon surface has led to process modifications that result in improvements in both the short‐circuit current density and the open‐circuit voltage of the cell. With these improvements, the cells exhibit AMl conversion efficiencies of nearly 17%. The fabrication process is reliable and reproducible with exceptionally high yield.

ISSN:0003-6951    

DOI:10.1063/1.90311

出版商:AIP    

年代:1978

数据来源: AIP