Ga1−xInxAs alloys in the composition range 0≤x≥0.52 and band-gap (Eg) range of 1.38 to 0.74 eV were activated with Cs and O2. Samples of different carrier concentrations were investigated. For band gaps down to about 0.8 eV, the photothreshold was equal to the band gap. The longest wavelength threshold determined was 1.58 μm. To the best of our knowledge, this represents the longest wavelength response yet achieved for photoemission into vacuum from a III-V compound. The surface escape probability, B, was derived from the quantum yield data for each sample. The B-vs-Eg data were analyzed according to a surface escape model which includes the effects of (i) a finite-width initial energy distribution of photoexcited carriers, (ii) the bent-band region and (iii) various types of surface potential barriers. Surface escape probability data pertaining to a single doping density could be explained by a model that includes only a work-function barrier or simple step potential. However, in order to explain the data for the several doping concentrations in a consistent manner, it was necessary to include an electron-semitransparent energy barrier above the vacuum level. A barrier width of 8 Å gives good agreement with the experimental data. This dimension is consistent with the thickness of the Cs–O activation layer which was experimentally determined to be on the order of a monolayer. These results are interpreted in terms of a surface double-dipole model.

Epitaxial layers of single‐crystal In1−xGaxP have been deposited on normalGaP substrates by an open‐tube vapor‐growth technique. The dependence of alloy composition on the deposition temperature and the relative amounts of In and Ga transported have been established. The effects of substrate preparation, reaction temperatures, deviations from equilibrium, and gas‐phase mixing on achieving material with controlled composition, purity, doping, and homogeneity have been investigated. In situ vapor‐grown p‐n junction structures employing Se and Zn as the respective n‐ and p‐type dopants have been prepared with sufficient perfection to permit fabrication of efficient visible‐light‐emitting diodes and injection lasers.

The vapor-hydride method of GaAs epitaxial growth permits separate control of the flow rates of both the AsH~ and HC1 reactant species. In the present work, these variables have been independently adjusted to provide gas-phase compositions ranging from Ga-rich to As-rich. The surface defect morphology has been found to be a strong function of the HC1 flow rate, changing from pits at low flow rates to hillocks at higher flow rates. In contrast, the AsH3 flow rate for constant HC1 flows principally affects the size of the defects. The growth rate increases slightly with increasing AsHs flow rate, but decreases with increasing HC1 flow rate over the range normally used. The Se-donor and Zn-acceptor concentrations both decrease with increasing HC1 flow rate, suggesting that crystal stoichiometry is not strongly influenced by the HC1 flow rate.Electroluminescent diode efficiencies range between 0.1 and 0.5% at room temperature and between 1 and 2.6% at 80~Peak efficiency values have been attained with slightly As-rich gas-phase conditions. * Electrochemical Society Active Member.

We have observed laser action at λ=3.06 μm in In0.77Ga0.23As0.74Sb0.26/InP0.7Sb0.3 double heterojunction, diode lasers, which were grown by organometallic vapor-phase epitaxy. The maximum operating temperature was T=35 K, and typical threshold current densities were 200–330 A/cm2. At temperatures up to 35 K, the lasing wavelength decreased with increasing temperature owing to a band-filling effect.

Erratum: Preparation, microstructure, and highfield superconducting properties of Nb3 Sn doped with groupIII, IV, V, and VI elements