摘要:

Nonequilibrium solid solubility of P, As, and B in single‐crystalline silicon annealed byQ‐switched ruby laser pulse irradiation was experimentally investigated for residual defects, lattice strain, and electrical activation of implanted impurities. The maximum solubility obtained without any macroscopically extended defect formation was 2–4 times higher than the thermal equilibrium solubility limit. Above this solubility, precipitates, dislocations, and surface cracks were observed. The highest full activation was realized by P implantation, with carrier concentration up to ∼5×1021/cm3showing no such defects. Formation mechanisms of the defects are discussed and shown to be attributable to the rapid solidification process of the heavily doped layer and to large impurity‐induced misfit stress comparable to the fracture stress.

ISSN:0021-8979    

DOI:10.1063/1.328050

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A possible role of impurities in the well‐known difficulty of obtaining well‐conducting large‐band‐gap material is investigated. Specifically, the limitations imposed on carrier concentrations by chemical equilibrium considerations are analyzed for a (model) system of a single amphoteric impurity. It is also shown that energies of formation of at least some Group‐I interstitials in a typical II–VI semiconductor, ZnSe, are expected to be low compared to those of native donor defects. Since Group‐I impurities act as acceptors on a metal substitutional site, but as donors when on a interstitial site, a stable interstitial form results in amphoteric behavior and thus in constraints on achievable carrier concentrations if such impurities are present either deliberately or accidentally.

ISSN:0021-8979    

DOI:10.1063/1.328051

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The Bloch‐wave characteristic impedance as well as the Bloch‐wave propagation constant of a rectangular waveguide periodically loaded with a series of thin, circular, centrally located, metal posts along the direction of propagation has been investigated both theoretically and experimentally. The theoretical analysis has been made to explore the frequency dependence of the real and imaginary parts of the Bloch‐wave characteristic impedance. As a part of the analysis, the study of the &ohgr;‐&bgr; diagram has also been exercised. The experimentally obtained data show agreement with the theoretical results.

ISSN:0021-8979    

DOI:10.1063/1.328052

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A chemical vapor deposition method capable of depositing high‐quality epitaxial layers of CdS on single‐crystal substrates has been employed for the fabrication of heterojunction photovoltaic devices of the typen‐CdS/p‐InP,n‐CdS/p‐CdTe,n‐CdS/p‐GaAs, andn‐CdS/p‐Ge. Analysis of the photovoltaic responses shows that all the devices generally have good collection efficiency, i.e., that at zero bias, photogenerated carriers crossing the junction do not suffer appreciable recombination at interface states. The solar energy conversion efficiency is, however, strongly influenced by the interface states through the open circuit voltage and the fill factor. Analysis of the dark current‐voltage characteristics shows the existence of a low‐temperature low‐bias voltage tunneling current in all of the devices. In at least two devices,n‐CdS/p‐InP andn‐CdS/p‐CdTe, there exists, at temperatures equal to or higher than 300 °K, a tunneling recombination current which flows through states near or at the interface with a thermal activation energy of about 0.6 eV.

ISSN:0021-8979    

DOI:10.1063/1.328053

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

By new activation methods, namely, activation by Cs, Sb, and O2(our former new method), or Cs, Ag, and O2(our present new method), stabilized negative electron affinity (NEA) cold cathodes can be obtained, and continuous operation over 6000 h has been achieved with GaP‐GaAlP cold cathodes at emission current density of about 10−1A/cm2. It is found that a major source of rapid degradation of the cold cathode is the loss of the activation material from NEA surface because of nonthermal equilibrium for the activation material. By the new activation methods, the efficiency of the cold cathode showed an increase of 20 ∼60% over that of the conventional method.

ISSN:0021-8979    

DOI:10.1063/1.328054

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Some types of Josephson junctions such as long microbridges,S‐N‐Sjunctions, and junctions with a series palastic inductance are known to have nonsinusoidal current‐phase relations which can be approximated by linear‐periodic functions. In this paper the equivalent circuit equation of the resistively shunted junction model with linear‐periodic current‐phase relation is solved. The heights of zeroth and first constant‐voltage steps in the I‐V characteristics and the impedance at these steps are obtained analytically. This analysis shows that the impedance at the first step lies on a semicircle in the impedance plane with its center at the impedance of the zeroth step. The calculated impedance is compared with the experimental results by Claridgeetal. The theory presented here can explain some features of experimental results which differ considerably from predictions based on a sinusoidal current‐phase relation. Among these are the value of bias current corresponding to the center of the first step, and the appearance of ’’shoulders’’ in the imaginary part of the impedance at the first step.

ISSN:0021-8979    

DOI:10.1063/1.328055

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Metal‐oxide‐semiconductor diodes have been fabricated onp‐type Wacker polycrystalline silicon with aluminum barrier metal, and semiconductor‐oxide‐semiconductor diodes have been fabricated by chemical spraying of indium‐tin oxide onn‐type single‐crystal silicon. The current‐voltage and capacitance‐voltage characteristics of these diodes have been measured at various values of temperature above 300 K and analyzed. The results indicate the likelihood of the primary transport mechanism’s being multistep tunneling instead of thermionic emission or minority carrier injection. The study also stresses the importance of investigating the temperature dependence of electrical characteristics before any firm conclusions may be drawn about the conduction mechanisms in semiconductor junctions.

ISSN:0021-8979    

DOI:10.1063/1.328056

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

This paper reports the investigations carried out on isotopic enrichment in boron oxide plasma produced by a Nd : glass laser giving 20 MW in 30 nsec (FWHM). Energy distributions of various ions in the plasma expandinginvacuumwere obtained with an electrostatic ion analyzer. Energies corresponding to peaks of distribution forB+10andB+11were found to be different by the ratio of their masses, consistent with hydrodynamic expansion of plasma. An anomalously high ratio ofB+10toB+11ions as compared to their natural abundance was observed.

ISSN:0021-8979    

DOI:10.1063/1.328033

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The mechanisms of polarization in chloranil pellets have been investigated by thermally stimulated discharge and ac dielectric measurements. Polarization was found to be mainly due to trapping of charge carriers at molecular sites and grain boundaries. A small dipolar contribution was also observed. Release of charges from molecular sites and dipolar reorientation occurred at about 120 °C with activation energy 0.8 eV. Charges from grain boundaries were released at a higher temperature (about 158 °C). Activation energy was calculated to be 1.06 eV.

ISSN:0021-8979    

DOI:10.1063/1.328057

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A self‐consistent, steady‐state potential calculation is performed for a hollow, magnetized electron beam flowing in a cylindrical drift tube interrupted by a cavity. The dependence of limiting current on cavity length is also investigated.

ISSN:0021-8979    

DOI:10.1063/1.328058

出版商:AIP    

年代:1980

数据来源: AIP