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With x‐ray diffraction techniques, it is possible to routinely measure lattice parameters to several parts in 104 for thin‐film samples. However, measurements of lattice parameter changes for quaternary device structures several microns in width are not usually feasible with x‐ray diffraction techniques. For this reason, transmission electron microscopy has been used to determine the position of higher‐order Laue zone lines within convergent‐beam electron diffraction patterns from thin foil cross sections of planar quaternary layers grown on InP substrates. A calibration curve has been generated which describes the position of higher‐order Laue zone lines as a function of the lattice parameter determined from x‐ray diffraction measurements. For the active quaternary region of an elecro‐optical device structure, it is shown that ths calibration procedure may be sensitive to a relative change in lattice parameter as small as ±2 parts in 104.

During vapor phase epitaxy, PH3 is generally used to preserve InP substrates. While PH3 is effective in reducing thermal decomposition, we find that excessive PH3 can produce morphological imperfections on the substrate surface. It is shown that in the temperature range of 675 to 700°C there is an optimum PH3 pressure under which the InP substrate surface morphology remains unchanged.

Liquid phase epitaxy (LPE) has been used to grow planar buried In 1- x Ga x As y P 1- y /InP double heterostructures. It is show n that poor wipe-off after melt-back and subsequent epitaxial growth over the mesa results in melt-carry-over on the surface and walls of the buried mesa. These indium rich inclusions are sources of defects which propagate through the burying layers. Significant improvement in wipe-off is achieved by etching the indium charges prior to use and by utilizing a multiple melt-back process before the epitaxial growth of burying layers.

With the aid of far infrared transmission measurements on thick samples of bismuth in the Faraday geometry we have identified both the spin and combination resonance of the holes.

Cathodoluminescence together with secondary electron imaging techniques are employed to correlate morphological and electronic properties of the (11 2 1) face of n-CdTe before and after photoetching. It is shown first that the quantum efficiency of the Cathodoluminescence increases considerably after photoetching. This increase is attributed to the selective removal of defects from the CdTe surface after photoetching. Furthermore no spatial correlation is found between the uniformly distributed etch pits (≈10 9 cm −2 ) and material defects, e.g. dislocations, inclusions. Consequently the unique morphology of photoetched CdTe surfaces must be attributed to yet another property of the semiconductor surface, e.g. the variations in dopant distribution close (10–100 A) to the semiconductor surface.

In the liquid phase epitaxy on indium phosphide, the substrate,just prior to the growth of the first epitaxial layer, is commonly etched back with an indium melt to remove any thermallydegraded surface and to ensure uniform and consistent wetting.This procedure, however, often produces defects which degrade both planar and buried heterostructure devices. For planar edgeemitters and lasers, the resulting rippled surface morphology degrades device performance by scattering light. For buried heterostructures, the meltback in the regrowth step leads to indium-rich inclusions. The effects of meltback on material quality are presented, and a new multiple meltback procedure which maintains flat surface morphology and eliminates inclusions is described.

A 1.3 μm InP/InGaAsP channelled-substrate buried-heterostructure laser is monolithically integrated with a monitoring photodetector. The lasers have threshold currents in the range of 25–30 mA and the photodetector provides ∼ 15 μA of photocurrent per milliwatt of laser power.

A new type of a simple gain-guided GaAlAs laser using a Schottky barrier restriction (SBR) technique is presented. Low current thresholds of ~2.2 kA/cm2, CW operation up to 70°C with a T0 = 160°, and a high coupling efficiency to multimode fibres are comparable to the high-quality lasers prepared with more traditional current restriction methods. This excellent performance has been achieved with extremely simple processing afforded by the SBR scheme. Although these SBR lasers have not yet been subjected to aging tests, GaAIAs LEDs fabricated in an identical fashion show excellent reliability.

Measurements of the specific contact resistance on epitaxially grown layers of p-In1−xGaxAsyP1−y as a function of composition demonstrate the resistance minimum of 7×10−6 Ωcm2 for In0.53Ga0.47As. Growth procedures for the preparation of InGaAsP/InP double-heterostructure LED wafers incorporating such a ternary InGaAs contact layer are described. This contacting technique allows fabrication of high-performance devices with reproducibly low series resistance.

Narrow-stripe, V-groove edge-emitting 1.3 μm LEDs are reported that couple -15.2 dBm of peak power into a single-mode fibre. Transmission at 180 Mbit/s over 35 km of single-mode fibre is described; this result corresponds to the highest bit rate-distance product (6.3 Gbit km/s) reported to date for an LED source. Accelerated aging results are presented.

The potential of InGaAsP light-emitting diodes (l.e.d.s) as light sources for quantitative absorption measurements in the 0.9–1.6 μm region is discussed. Since a variety of chemicals, including atmospheric water vapour and pollutants such as CO2 and NO2 have absorption bands in the spectral region spanned by InGaAsP l.e.d.s, this technique is useful in evaluating impurity content. Detection of the atmospheric water vapour band centred at 1.38 μm is demonstrated. The application of this technique for assessing the OH content of optical fibres is also discussed.