Reducing dislocations in gallium arsenide on silicon templates

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University of California Santa Barbara (UCSB) in the USA has been working to optimize gallium arsenide (GaAs) molecular beam epitaxy (MBE) on gallium phosphide on silicon (GaP/Si) [Daehwan Jung et al, J. Appl. Phys., vol122, p225703, 2017]. Normally, growth of GaAs on Si uses off-axis substrates in efforts to avoid anti-phase domains. On-axis silicon is preferred for compatibility with CMOS processing foundries. The lattice mismatch between GaAs and Si is ~4%, leading to dislocations.

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Room-temperature PL spectra of GaAs PL samples grown on native GaAs, and three different GaAs/GaP/Si templates.