Spontaneously generated effective-mass lateral superlattices

Abstract

An alternative approach to synthesizing effective-mass lateral superlattices is proposed. We show theoretically that the coherency strain associated with spontaneous lateral composition modulation provides a negative feedback which results in a band-gap locking phenomenon but that the resulting longitudinal strain wave breaks the symmetry of the valence bands, thereby generating an effective-mass lateral superlattice.

Linear and second-order optical response of III-V monolayer superlattices

“…In particular III-V semiconductor hetero-structures and SLs have attracted a great deal of interest mainly due to the possibility of tailoring band gaps and band structures 1,2,3,4,5 by variation of simple parameters like superlattice period, growth direction and substrate material. With the development of new techniques like the strain induced lateral ordering process 6 and existing methods like molecular beam epitaxy 7 and low-pressure chemical-vapor deposition 8 it is possible to grow and tailor these SLs. Thus a great deal of experimental work has been devoted to these materials.…”

Spatial variations in luminescence and carrier relaxation in molecular beam epitaxial grown (InP)2/(GaP)2 quantum wires

“…The broad peaks located in the 680ՇՇ750 nm range are due to emission from the QWR array. [9][10][11][12][13][14] The CL spectral line shapes are observed to vary with beam energy, particularly for sample 2067, which shows a marked enhancement in the high-energy side of the line shape for higher beam energies. Spectra taken at E b ϭ 3 keV, for both samples, show a line shape very similar to that of PL obtained with an argon-ion laser ͑not shown here͒.…”

“…This strain induced lateral ordering ͑SILO͒ method has been utilized to form quantum wire ͑QWR͒ arrays in bilayer superlattices ͑BSLs͒ of ͑InP͒ 2 /͑GaP͒ 2 and ͑GaAs͒ 2 /͑InAs͒ 2 grown on a GaAs͑001͒ or InP͑001͒ substrate, respectively. [9][10][11][12][13][14] The optical properties of the QWR structures have been studied with photoluminescence ͑PL͒, 9,10 photoreflectance ͑PR͒, 11 and cathodoluminescence ͑CL͒ 12-14 techniques. A large polarization anistropy was found to be consistent with the existence of QWRs.…”

Optical anisotropy in InP string-like aligned quantum dots

“…Two pronounced photoluminescence (PL) emission peaks emerge, which are identified as transitions of normal QDs and SQDs. We found that under the strain field, such aligned SQDs and normal QDs exhibit strong optical polarization anisotropy while rotating the PL probe polarizer from the [1][2][3][4][5][6][7][8][9][10] to the [110] crystal direction. We also observed a spectral blue-shift while changing the polarization direction.…”

“…Lateral composition modulation (LCM) in compound semiconductors is an example of the consequence of a strain-induced heterostructure [1][2][3] wherein different atoms cross-penetrate and develop a periodic modulation of the quantum structure along the lateral [110] crystal direction; hence, the [1][2][3][4][5][6][7][8][9][10] crystal direction becomes the plane of the well and the barrier. Such lateral semiconductor heterostructures exhibit pronounced optical properties such as optical polarization anisotropy or spectral energy shifts along the [110] and the [1][2][3][4][5][6][7][8][9][10] directions due to the biaxial strain fields [4][5][6]. Another example is the growth of Stranski-Krastanov (SK)-mode self-assembled quantum dots (QDs).…”