Aluminum-free strained-layer lasers emitting at 1.14 μm on low-composition InGaAs:n substrates by metalorganic chemical vapor deposition
Broad-area (W=150 /spl mu/m) single-quantum-well (SQW) lasers have been successfully fabricated on n-type In/sub 0.03/Ga/sub 0.97/As substrates without incorporating aluminum-containing alloys. The strained-layer InGaP-GaAs-InGaAs heterostructure was grown by atmospheric pressure metalorganic chemical vapor deposition. Due to both the increased substrate lattice constant and the partial strain compensation supplied by the tensile-strained GaAs optical guiding layers, a peak emission wavelength of 1.1403 /spl mu/m is obtained for a 1-mm cavity length.
Optical and Electrical Characterization of Melt-Grown Bulk Indium Gallium Arsenide and Indium Arsenic Phosphide Alloys
Abstract : A new method to determine semiconductor bandgap energy directly from the easily measured transmission spectra was developed. The method was verified using many binary semiconductors with known properties and utilized to determine the unknown ternary semiconductors were determined at various wavelengths and temperatures. Photoluminescence and Hall-effect measurement were performed to identify various electronic transitions, as well as sample quality. The determination of electrical and optical properties of the material will provide important addition to the database of material properties for future optoelectronic device applications. In the near future, newer materials and their applications need to be developed, and often binary and ternary III-V compounds (GaSb, GaP, GaSbP etc.) can be studied using the method developed in this work.
Description of roughness profiles by separating the random and periodic components
Abstract The probability that it is not possible to obtain a significant description of roughness profiles composed of random and periodic components by using statistical methods is discussed. It is shown that the random and periodic components can be separated by using the frequency spectrum and the autocorrelation function of the profile. The physical significance of the separate components is discussed and it is shown that it is possible to describe a long crested surface by a single profile using these components The method of separating the random and periodic components allows a parametrical description of the roughness profile to be given. It is then possible to use these parameters to calculate a synthetic signal sign with the same basic properties as the measured profile.