Tailoring infrared optical properties with superlattices of superlattices
G.T. Einevoll; L.J. Sham , Department of Physics, University of
California, San Diego, La Jolla, California 92093-0319
Physical Review B 46, 7787-7793 (1992)
Abstract
A new concept, superlattices of superlattices (SOS), is introduced to
tailor infrared optical properties in semiconductor devices.
SOS structures are constructed by alternating two different superlattices.
By describing the separate
superlattice sections in terms of their miniband edges and miniband-edge
effective masses, and by using these parameters as input in a
nested effective-mass theory,
a transparent connection between the choice of material parameters and
device properties is obtained. As one example of application we
use the concept to propose SOS infrared detectors with more
flexibility and potentially better performance compared to
photodetectors based on conventional superlattices.
In another example the idea is applied to lateral superlattices.
It is shown that the desirable
features of the SOS structures are robust against disorder in the
layer thicknesses.