The effects of addition of a series of organoamine molecules on the luminescence of porous silicon has been examined by steady-state photoluminescence (PL) and Fourier transform infrared spectroscopies. These samples, prepared nonanodically via stain etching techniques and characterized by atomic force microscopy, show dramatic quenching of visible PL upon addition of dilute solutions of the above Lewis base adsorbates. The fractional changes in integrated PL intensity as a function of quencher concentration obey a simple equilibrium model, demonstrating Langmuir-type behavior from which equilibrium constants can be calculated. An observation concomitant with this loss of PL is a diminution of the silicon hydride stretching frequencies near 2100 cm−1.

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The influence of sonication on the surface structure and chemical stability of porous silicon (PS) thin films prepared by an open‐circuit stain‐etch is described. An analysis of differences in surface morphologies by atomic force microscopy between samples prepared either in the presence or absence of sonication reveals that sonication generates a relatively rougher, thicker film as evidenced by the magnitudes of average and root‐mean square surface roughness false(Rnormalafalse) and the maximum height of surface features. These differences result in stain‐etch porous Si films possessing greater chemical stability to exposure to reagents such as water and organoamines.

The utility of in situ laser light scattering (LLS) to monitor molecular beam epitaxy growth of InGaAs/GaAs strained layers is demonstrated. LLS signatures were correlated with ex situ characterization by x-ray diffraction, transmission electron microscopy, and atomic force microscopy. Desorption of GaAs native oxide resulted in surface pit formation (3–10 nm depth, 30–100 nm width, density of 109–1010 cm−2) which caused a slight increase in LLS signal. Deposition of a GaAs buffer layer reduced the surface pitting, then formed a wavy surface morphology, with step deviations of ∼5 monolayers which were aligned in the (011̄) direction. InGaAs layer growth at 515 °C resulted in a rapid increase in LLS intensity, after an initial onset time, because of the increasing density and height of surface steps generated by misfit dislocations. Critical thickness was determined in situ from the LLS onset time, which depended inversely on the InGaAs composition, and was compared to equilibrium model predictions. By rotating the wafer, contributions to the LLS signal from misfit dislocations could be separated from isotropic surface roughness. Three-dimensional (island) growth occurred in films with In content above 25%. Observations of relaxation dynamics included the continuing increase of LLS signal even afer InGaAs layer growth was terminated. During GaAs cap layer growth, a decrease in the density ratio of α(011̄) to β(001) dislocations was also observed.