InxAl1-xAs/InyAl1-yAs vertical superlattices (VS) were naturally formed by phase separation during the growth of InAlAs/InP layers at temperatures in the range 565-615°C by metalorganic chemical vapor deposition. The VS lies perpendicular to the (001) growth plane. As the growth temperature increased from 565 to 615°C, the VS decreased in thickness from ∼15 to ∼6 nm, and became less planar and uniform. Transmission electron diffraction results showed the occurrence of CuPt-type ordering in some of the layers. Band-gap reduction of ∼300 meV was observed in the InAlAs layers grown at temperatures ranging from 565 to 615°C. Such a large reduction in band-gap energy was attributed to combined effects of the VS and CuPt-type ordering.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)