Search

The numerical calculations to study the contributions of each component of the current are presented. The effect of the series resistance on the current-voltage characteristics and the influence of defects on the photodetector response time and on the rejection ratio are discussed.

The drift experiments are conducted on pure Al, polycrystalline, unpassivated Belch-type test structures at a current density of 1.0 MA/cm(super 2) and at temperatures in the range 15-230 degree C. The new expressions have a significant impact on the determination of the critical length, extrapolation of the newly predicted parabolic dependence of the drift velocity on line length in the near-threshold regime results in a critical product of 670 plusmn 120 A/cm, well below the value obtained from the inverse linear extrapolation predicted by Blech.

The electron transport in GaAs/AlGaAs quantum cascade lasers in midinfrared is calculated self-consistently using an intersubband scattering model. The results can be used to calculate current densities, injection efficiencies and modal gain, and to estimate the output characteristics, including the gain coefficient and threshold current for a range of temperatures.

Damage evolution and subsequent recovery in 4H-SiC epitaxial layer irradiated with 1. 1 MeVAl(super 2+)(sub 2) molecular ions at 150 K to ion influences from 1.5x10(super 13) to 2.25x10(super 14) Al cm(super -2) were studied by Rutherford backscattering spectroscopy (RBS) and (super 12)C(d , p)(super 13)C nuclear reaction analysis (NRA). The results show that the atomic disorder on both the Si and C sublattices increases nonlinearly with ion influence at 150 K eventually achieving a fully amorphous state at a dose of about 0.12 dpa.

Five electron traps were found with junction grown by liquid phase epitaxy (LPE) using deep level transient spectroscopy (DLTS) in GaAs:Si and AlGaAs:Si. All the traps showed which showed different features were confirmed to be DX centers.

The superlattice Schrodinger equation is solved for systems with potential profile modified by charge polarization in opposite interfaces. With the solutions band displacement and intraband energy levels can be determined for different layers widths, internal electric fields and time of life of the excited particles.

The polycrystalline LaAl(sub x)Ni(sub 5-x) suitable for ultrasonic measurement was produced by hot isotonic pressing technique. The elastic moduli of the same were determined by resonant ultrasound spectroscopy and by ultra sonic pulse-echo technique.

Microwave (30 GHz) measurements on aluminum superconducting hot-electron bolometer (HEB) mixers are discussed. The microwave heterodyne mixing results show good performance with a mixer noise temperature inferred from the conversion efficiency and output noise of T(sub M) more than or equal to 4 K, double size band (DSB).

The electrical properties and the characteristics of GaN and AlGaN heterojunction diodes are investigated with varying Al composition. The tunnel assisted recombination model agreed well with both current-voltage and capacitance-voltage measurements for this diode.

A governing parameter, called AFD(sub gen)(super star), which reflects electromigration damage in a polycrystalline line covered with a passivation layer is formulated. The usefulness of the AFD(sub gen)(super star) is given through a discussion on the validity of the film characteristic constants obtained in both covered and uncovered metal lines made of same Al film.

The relation between optical and transport properties of a GaAs/AlAs super lattice-like double-barrier diode is studied. It can be explained in terms of the temperature-dependent transport properties of the minority carriers in the collector spacer layer.

In silicon solar cell fabrication, impurity gettering from Si by an aluminum layer and diffusion of Al for creating the back surface held (BSF) are inherently carried out in the same process. Model provides a means for optimization of the temperature regime for both processes, as well as for maximization of solar sell efficiency.

Hole-initiated avalanche multiplication is investigated using an AlGaAs/InGaAs p-n-p heterojunction bipolar transistor (HBT). Threshold energy of 2.5 eV was determined to be suitable for describing the hole-initiated impact ionization process.

Reports regarding in-plane electrical transport in n-type selectively doped GaSb/AlGaSb multiquantum wells are discussed. Acceptable values of delta were obtained, consistent with results of structural investigations in single quantum well samples of GaSb/Al(sub 0.40)Ga(sub 0.60)Sb.

In situ MAS NMR spectroscopy under continuous-flow conditions and spin-echo NMR experiments is applied to investigate the quadrupolar interactions of framework aluminum atoms in zeolite H-ZSM-5 at elevated temperatures and during conversion of methanol. The study can be explained by jumps of the hydroxyl protons between two or three of the energetically favored oxygen atoms of each aluminum site or between different aluminum sites.

The gas-phase Si and Al oxyanions were formed by particle bombardment, isolated by mass, and then reacted with H2S in an ion trap secondary ion mass spectrometer. The radical anion SiO2.- reacted with H2S by abstracting a .SH radical to form the even-electron SiO2SH(super -).

An investigation was carried out of the ground electronic structure of the carbides BC and AlC, the ground and the first two excited states of the corresponding anions, BC(super -) and AlC(super -), the ground structures of the hydrides H-BC and H-AlC. The ground state of BC and AlC is of (super 4)Sigma(super -) symmetry; (super 3)pi is the ground state of the anions BC(super -) and AlC(super -).

The effect of filler surface group on the conductivity, ion-ion, ion-polymer interactions and microstructure of PEG-LiClO(sub 4)-Al(sub 2)O(sub 3) composite polymer electrolytes is examined. The addition of the filler results in the changes in ionic association as studied by FT-IR and by applying the Fuoss-Kraus formalism to the slat concentration dependence of the molar conductivity of the composite electrolytes studied.

The vibrational modes of double four-member ring fragments (D4R), where Si and Al occupy tetrahedral sites and M(super +) is a monovalent charge compensating cation, are assigned to the framework vibrations of Linde type A (LTA) zeolites. The normal vibrations that arise from configurations with different Si, Al arrangements are calculated by the B3LYP method.

Several experimental and theoretical researches are conducted to understand the interface chemistry between Alq3 thin films and the metals that are deposited on its cathodes. Spectroscopic data show that formation of metal-Alq3 complexes takes place at the interface in the early stage of metal deposition.