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We have evaluated the Burstein-Moss ͑BM͒ shift at 300 K in seven samples of n-In 0.53 Ga 0.47 As (1.3 ϫ10 16 рnр3.9ϫ10 19 cm Ϫ3 ) lattice matched to InP using spectral ellipsometry in the range of 0.4-5.1 eV. The data have been fitted over the entire spectral range to a model reported by Holden et al. ͓in Thermphotovoltaic Generation of Electricity, edited by T. J. Coutts, J. P. Brenner, and C. S. Allman, AIP Conf. Proc. No. 460 ͑AIP, Woodbury, NY, 1999͒, p. 39͔, based on the electronic energy-band structure near critical points plus relevant discrete and continuum excitonic effects. A Fermi-level filling factor in the region of the fundamental gap has been used to account for the BM effect. While our data exhibit nonparabolic effects, with a blueshift of 415 meV for the most highly doped sample, we did not observe the Fermi-level saturation at 130 meV for nу10 19 cm Ϫ3 reported by Tsukernik et al. . Our BM displacements are in agreement with a modified full-potential linearized augmented-plane-wave calculation ͓G. W. Charache et al., J. Appl. Phys. 86, 452 ͑1999͔͒ plus possible band-gap-reduction effects.The study of the Burstein-Moss ͑BM͒ effect in n-In 0.53 Ga 0.47 As lattice matched to InP is important from both fundamental and applied points of view. Recently Tsukernik et al. 1 presented an investigation of the BM shift in this material based on thermionic emission and diffusion over a barrier and concluded that the BM change saturates at about 130 meV for nу10 19 cm Ϫ3 . This observation was explained as a ''Fermi-level saturation;'' based on their results the authors called for a reexamination of existing theories. In contrast, Charache et al. 2 and Holden et al. 3 did not observe such a Fermi-level saturation in heavily doped n-In 0.66 Ga 0.34 As. Structures based on highly n-doped In 0.53 Ga 0.47 As materials have been used for several kinds of semiconductor devices such as heterojunction bipolar transistors, 4 resonant-tunneling devices, 5 and Bragg reflectors for surface-emitting lasers. 6 For these kinds of applications it is highly desirable to have information about the position of the Fermi level relative to the conduction-band edge.We present a study of the BM effect at 300 K in seven samples of n-In 0.53 Ga 0.47 As (1.3ϫ10 16 рnр3.9ϫ10 19 cm Ϫ3 ) lattice matched to InP using spectral ellipsometry. The data have been fitted using a comprehensive model 3,7 based on the electronic energy-band structure near critical points plus relevant discrete and continuum excitonic effects. The BM shift at the direct gap was accounted for using a Fermi-level filling factor in addition to the discrete and continuum excitonic terms. 3 The Fermi-level alteration exhibits nonparabolic effects. However, in contrast to Ref. 1, we did not observe a Fermi-level saturation. Our results exhibit a blueshift of 415 meV for the highest doped sample (nϭ3.9 ϫ10 19 cm Ϫ3 ). The BM displacements of this work are in agreement with a modified full-potential linearized augmented-plane-wave ͑FLAPW͒ calculation 2 plus possible band-...

We demonstrate that nanomechanically stamped substrates can be used as templates to pattern and direct the self-assembly of epitaxial quantum structures such as quantum dots. Diamond probe tips are used to indent or stamp the surface of GaAs(100) to create nanoscale volumes of dislocation-mediated deformation, which alter the growth surface strain. These strained sites act to bias nucleation, hence allowing for selective growth of InAs quantum dots. Patterns of quantum dots are observed to form above the underlying nanostamped template. The strain state of the patterned structures is characterized by micro-Raman spectroscopy. The potential of using nanoprobe tips as a quantum dot nanofabrication technology are discussed.