摘要:

A diffusion model for the collection efficiency ofa‐SiHxSchottky‐barrier solar cells is found to be in excellent agreement with experimental data. This model accounts for the poor short‐wavelength response of these devices and suggests a way for improving their performance.

ISSN:0003-6951    

DOI:10.1063/1.92265

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We have performed a Monte Carlo simulation of high‐field transport in GaAs using a realistic band structure obtained by the empirical pseudopotential method. On this basis, a detailed study of the band structure dependence of impact ionization in GaAs is given. Our method avoids the use of the effective mass theorem or the Kane model of nonparabolicity, which are no longer accurate at high electron energies. We show (i) that the orientation dependence of the impact ionization rate is negligibly small, (ii) that the saturation velocity of electrons in GaAs is close to 6×106cm/s at extremely high fields (this value is determined to a large extent by the band structure, and (iii) that the previous theories of impact ionization as given by Wolff, Shockley, and Baraff have numerous limitations.

ISSN:0003-6951    

DOI:10.1063/1.92266

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A grossly inhomogeneous, noncolumnar morphology has been observed in doped, plasma‐deposited hydrogenated amorphous silicon (a‐Si:H) within critical ranges of the diborane to silane ratio in the gas phase. The diborane level can be as low as 5 ppm and depends both on the electrode self‐bias potential and the growth rate. Undoped specimens prepared under the same deposition conditions have properties typical of device‐gradea‐Si:H. These morphology observations suggest a structural origin for some doping‐dependent properties ina‐Si:H.

ISSN:0003-6951    

DOI:10.1063/1.92267

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

High‐voltage electron microscopy (HVEM) has been used for the investigation of the defect structure in cw laser‐annealed silicon. We report for the first time a (HVEM) analysis of the formation processes involved in the nucleation and glide of slip dislocations during epitaxial regrowth by cw laser annealing of ion‐implantation damaged silicon layers. Based on the combined optical and HVEM observations a model of the dislocation generation and glide processes is presented.

ISSN:0003-6951    

DOI:10.1063/1.92268

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The barrier height at the anodic oxide/GaAs interface has been determined by internal photoemission of the metal‐oxide‐semiconductor structures. The height of the potential barrier between the oxide and GaAs is found to be 2.62±0.05 eV for as‐grown and 2.39±0.05 eV for hydrogen‐annealed specimens. Quantum yield below the photoemission threshold is interpreted in terms of electron emission from interface states at energies above midgap of GaAs.

ISSN:0003-6951    

DOI:10.1063/1.92269

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report on the evidence from photoluminescence measurements of the relative positions of the localizedd‐levels of the Mn2+ions with respect to the conduction and valence bands of Cd1−xMnxTe. The results indicate that the ground state6Sis approximately 0.8 eV inside the valence band for all compositions up tox=0.7. The first excited state4Gis deep inside the gap, and it represents an energy level that may substantially affect the lifetime and recombination characteristics of the carriers in the Cd1−xMnxTe system.

ISSN:0003-6951    

DOI:10.1063/1.92270

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The acoustoelectric method of determining carrier mobility &mgr; in semiconductor films has been modified to permit its application to high‐resistance, low‐mobility films. The conventional method requires knowledge of the acoustic loss caused by the mobile carriers; in high‐resistance films this loss becomes too small to be measured. We show that the required information may be derived from knowledge of the acoustic power and the device geometry. Our samples were amorphous hydrogenated Si and Si0.6Ge0.4films on nonpiezoelectric substrates, separated by a convenient air gap (12.5 &mgr;m) from a LiNb03slab carrying surface acoustic waves. One sample had 108&OHgr;/&laplac; and &mgr;=0.08 cm2/V sec, another sample 1010&OHgr;/&laplac; and &mgr;=0.5 cm2/V sec.

ISSN:0003-6951    

DOI:10.1063/1.92257

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report a new picosecond optical technique for observation of nonequilibrium carrier transport. An ’’overshoot’’ electron velocity of 4.4×107cm/sec is observed at short times in GaAs under appropriate electric field conditions.

ISSN:0003-6951    

DOI:10.1063/1.92258

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The possibility of controlling the growth of nickel silicide by implanting N into thin Ni films evaporated on Si substrates has been studied using4He backscattering spectrometry. The reaction between Ni and Si is completely halted below annealing temperatures of ∼375 °C by implanted doses of 5×1016N/cm2. At higher annealing temperatures, localized intermixing takes place. For low doses ≲0.5×1016N/cm2, the reaction between Ni and Si is that observed for unimplanted samples both in the phase formed (Ni2Si) and in rate of growth. For intermediate doses ∼0.9×1016N/cm2, the first phase formed corresponds to NiSi, and the growth rate is greatly reduced. These results are explained in terms of a silicon nitride barrier to Ni diffusion forming at the Ni/Si interface.

ISSN:0003-6951    

DOI:10.1063/1.92259

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A new procedure of generating ultrahigh pulsed magnetic field was described. The method is based on the fact that semiconducting materials undergo shock‐induced metallic transition at very high pressures. An approximate numerical analysis using the magnetohydrodynamics equations was carried out for silicon with normal and low initial densities. It is shown that flux concentration may become efficient for low‐impedance materaials.

ISSN:0003-6951    

DOI:10.1063/1.92260

出版商:AIP    

年代:1981

数据来源: AIP