“…Several techniques, including two-step growth [5][6][7], strained-layer superlattice [8], post-annealing [9,10], epitaxial lateral overgrowth (ELO) [11], and AlGaInAs graded buffers [12,13], have been investigated to reduce the defect density of an InP/GaAs virtual substrate. The two-step method, which was developed early to grow GaAs on Si, was simple and useful.…”