摘要:

The trapping range of holes and electrons in amorphous selenium layers has been measured with a voltage decay technique. Values of 1.1 to 7.8×10−8cm2/V were obtained for holes. This agreed well with values obtained by the pulse method. An electron range of 5.0 to 8.3×10−8cm2/V was measured. Quantum efficiencies for photoexcitation of holes and electrons ranged from 7.5×10−4to 1.0, depending on the wavelength of the incident light.

ISSN:0021-8979    

DOI:10.1063/1.1713756

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

Adsorbed oxygen increases both the response and the response time for the photovoltaic effect in rutile.The model for the effect of chemisorbed oxygen on the photoconductivity has been modified to take into consideration the effect of oxygen pressure. The conductance of rutile, measured as a function of oxygen pressure, agrees with the modified model.The increase in photovoltaic response and response time with exposure to oxygen has been explained in terms of the barrier layer formed by chemisorbed oxygen.

ISSN:0021-8979    

DOI:10.1063/1.1713757

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

The ultraviolet photovoltaic response of barrier‐layer cells formed from single‐crystal rutile has been investigated. Typical samples have response maxima at 3200 Å, aD* of 109cm cps1/2/W, and time constants of 100 &mgr;sec. Variations in time constant over several orders of magnitude have been observed, dependent largely on preparative technique. The effect of surface treatment on cell characteristics is discussed.

ISSN:0021-8979    

DOI:10.1063/1.1713758

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

The operation is described of a novel dielectric element which can stabilize its own temperature within narrow limits in the highly nonlinear region close to the Curie temperature. The device employs a triglycine sulphate (TGS) single crystal, and its operation is based on heating due to dielectric loss that is a strong function of temperature near the Curie point. The element operating in this autostabilizing state exhibits extremely high dielectric nonlinearities up to the high‐frequency region, the nonlinearities being only little dependent on the changes of ambient temperature, which was experimentally proved in the range from −35° to +45°C. The element has various applications; e.g., frequency multiplier, mixer, frequency modulator, pulse position modulator, dielectric amplifier, electrometer, electromechanical transducer, transducer sensitive to heat transfer, etc.

ISSN:0021-8979    

DOI:10.1063/1.1713759

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

A simplified explanation of the automatic temperature stabilization of a nonlinear dielectric element is presented. The explanation is based on energy considerations of the heat produced in consequence of dielectric losses in the element and of heat transferred to the ambient medium. The principle of bringing the element into the autostabilizing state is discussed in detail, as well as the falling out of this state, and the nature of temperature hysteresis of this element is explained. Measurements of complex permittivity at the fundamental frequency and high amplitudes of applied voltage as functions of crystal temperature are given for various values of the heating voltage. From these experimental results the temperature stabilization of the element is calculated for its dependence on variations of ambient temperature and heating voltage; a good agreement was found with the experimental values previously reported. The principle of automatic stabilization of temperature is not limited to the TANDEL produced from a triglycine sulfate single crystal but can be realized with some other materials having a decreasing dependence of &egr;″ on the temperature.

ISSN:0021-8979    

DOI:10.1063/1.1713760

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

Infrared reflectance and Faraday rotation data were obtained for pure and for highly Al‐dopedn‐type ZnSe crystals. Comparison of these data gave the free‐carrier contribution to the dielectric constant and Faraday rotation, which, in turn, yielded the electron effective mass and carrier concentration. The result for the effective mass ratio,m*/m=0.17±0.025, agrees satisfactorily with previous estimates. The Hall scattering constantrwas obtained from the optically measured carrier concentration and Hall effect data on the optical samples. The result,r≃1.4, forN≃0.7Ndeg, is consistent with values found in other II‐VI compounds.

ISSN:0021-8979    

DOI:10.1063/1.1713761

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

Variable reactance epitaxial siliconp‐njunctions with approximately constant impurity gradients were investigated at 5.85 Gc/sec, 1 Mc/sec and dc between room temperature and 2°K. Thep‐njunctions were B‐P and B‐As doped. The units with breakdown voltages larger than 11V (at 300°K) showed an exponential freeze‐out of the carriers at 5.85 Gc/sec when the temperature was lowered. The units with less than 7.7 V breakdown voltage showed clearly impurity band conduction at low temperatures. The maximum change of the reactive component between large forward currents and the breakdown voltage was temperature independent within ±10% for all the wafers. The cutoff frequencies of the wafers at 300°K were between 190 and 320 Gc/sec. The units with large breakdown voltages (>14 V) had a negative differential resistance in the dc forward voltage‐current characteristics at low temperatures. From an extrapolation of the present experiments one would expect, when the impurity gradient at the junction is increased to such a value that the breakdown voltage is about 5.5 V, that epitaxial silicon variable reactancep‐njunctions will operate at microwave frequencies and liquid‐helium temperatures with approximately the same losses as at room temperature.

ISSN:0021-8979    

DOI:10.1063/1.1713762

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

The relationship between the voltage across GaAsp‐njunctions and the emission spectrum from carrier recombination in differently doped specimen has been carefully examined. The data are interpreted in terms of radiative recombination via levels 30 meV above the valence band edge. Furthermore, depending on the gradient of impurities in thep‐njunction, the transport mechanism is tunneling, injection, or a combination of both.

ISSN:0021-8979    

DOI:10.1063/1.1713763

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

A traveling solvent method has been used to grow GaP crystals from Ga solution. Growth rates of approximately 0.5 mm/h have been achieved at an average temperature as low as 850°C, from Ga zones 0.025 mm thick. Polycrystalline growth, 10 mm in diameter and 2 mm thick, has been achieved as a direct continuation of the crystal orientations in polycrystalline seeds.p‐njunction structures have been grown by doping from a 2% Ge‐Ga solvent zone. Some electrical characteristics of small diodes cut from polycrystalline crystals are described.

ISSN:0021-8979    

DOI:10.1063/1.1713764

出版商:AIP    

年代:1964

数据来源: AIP

摘要:

Spherulitic growth rate data for polyoxymethylene have been successfully analyzed with the recently proposed nucleation theory by Hoffman and co‐workers that assumes a coherent nucleation mechanism. Lamellar step heights, which were calculated as a function of the crystallization temperature, were in good agreement with experimental values obtained by Geil who used small angle x‐ray scattering. The surface free energy of the nucleus and the end free energy of the fold surface were calculated to be 10.5 and 26 ergs/cm2, respectively. These reasonable values lend further support to this kinetic analysis.

ISSN:0021-8979    

DOI:10.1063/1.1713765

出版商:AIP    

年代:1964

数据来源: AIP