Metastable GaAsBi alloy grown by molecular beam epitaxy

GaAs1-xBix has been grown at a substrate temperature (T-sub) between 350 and 410degreesC by molecular beam epitaxy. The relationship between GaBi molar fraction (x) evaluated by Rutherford backscattering spectroscopy and the lattice constant showed good linearity. To achieve Bi incorporation into the epilayer, As flux was adjusted in a limited range on the brink of As shortage on the growing surface. The Bi incorporation was saturated at a large Bi flux, probably due to a low miscibility of Bi with GaAs. The value of x increased up to 4.5% with decreasing T-sub to 350degreesC.