Relationship between compositional modulation and ordered structure in a Ga x ln1?x P epilayer

Relations between compositional modulation and atomic ordering degree in thin films of ternary III–V semiconductor alloys

“…All experiments, including transmission electron microscopy (TEM), [1−3] atomic force microscopy, [4,5] electron diffraction, [2] x-ray diffraction (XRD) [2,6,7] and nuclear magnetic resonance (NMR) [8,9] demonstrated that in A x B 1−x C epilayers A and B atoms on their group III sublattices often show spontaneously partially ordered structure because of surface-induced effects. [10,11] In partially ordered domains of A x B 1−x C epilayers, as shown in Fig.…”

“…1, the existence of alternating A-and B-enhanced planes on the group-III sublattices along (111) (CuPt-type) has been observed. [2,6] It also has been both experimentally and theoretically verified that the ordering of A and B atoms on their group III sublattices in A x B 1−x C epilayers decreases the bandgaps [12,13] and has an obvious influence on the material's electronic structure, phase transitions, thermodynamic stability, optical, magnetic, mechanical and transport properties. [13−20] A and B atoms on their group-III sublattices in A x B 1−x C epilayers, grown by different conditions and techniques, may show different types of ordering, including CuPt-, CuAu-and clustering-type, along different directions.…”

“…In XRD, [6] we have introduced enhanced factor ε (0≤ ε ≤ 0.5). If A and B atoms in a A x B 1−x C epilayer are distributed randomly on their group-III sublattices, there is ε = 0.…”

“…We have indicated that the modulation factor y can be determined by the composition x and enhanced factor ε [6] as follows:…”