Metastable GaAsBi Alloy Grown by Molecular Beam Epitaxy

GaAs 1- x Bi x has been grown at a substrate temperature ( T sub ) between 350 and 410°C 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 350°C.