High-quality InGaAsP grown on GaAs by solid source molecular beam epitaxy with a GaP decomposition source

InGaAsP quaternary epilayers were grown on GaAs [001] by solid source molecular beam epitaxy (SSMBE) using a valved GaP compound cell and a valved arsenic cracker cell. Due to elastic strain induced energy band gap shift, so the composition and lattice mismatch of In_xGa_1-xAs_yP_1-y were calculated using (004), (224) high-resolution X-ray diffraction and unstrained energy band gap E_g which was determined by the difference between room-temperature photoluminescence E₀ with elastic strain induced energy band gap shift. The 500 nm thick high-quality lattice matched InGaAsP epilayer on GaAs showed a lattice mismatch of -554 ppm, X-ray diffraction rocking curve linewidth as narrow as 31 arcsec and photoluminescence full width at half maximum (FWHM) as low as 4.4 meV at 24 K, which is comparable to the best previously reported other results. Thus, SSMBE with a GaP decomposition source is a promising technique for growth of high quality P-based compounds. We also found that the incorporation rate of arsenic is much higher than that of phosphorous.