Molecular Beam Epitaxy Growth of GaAsBi Using As2 and As4


Author: Robert D Richards, Faebian Bastiman, Christopher J Hunter, Danuta F Mendes, Abdul R Mohmad, John S Roberts, John P R David Elsevier Logo  | © Elsevier B.V. Journal of Crystal Growth
Date: 2014
Instruments: Custom MBE, LT STM, RHEED 30 kV, LT STM Lab

100 nm thick GaAsBi layers were grown at a range of temperatures using both As2 and As4. Measurements of Bi incorporation based on room temperature photoluminescence spectra indicate that the growth temperature dependence of Bi incorporation is the same for both As species and is invariant with respect to Bi flux; however, Bi incorporation saturates when the growth temperature is low enough for the Bi incorporation coefficient to reach unity. The As:Ga atomic flux ratios allowing significant Bi incorporation are coincident for both As species upon accounting for desorption of 50% of the incident As4 atoms during GaAs growth. The Bi reconstruction lifetime at 415 °C was measured under overpressures of both As species and under vacuum. The lifetime is significantly longer than the monolayer growth time used in this work; however, results do show that As2 is more aggressive at displacing Bi from a static surface than As4. The photoluminescence intensities of the samples grown in this work vary with Bi incorporation in accordance with current literature and appear to be independent of As species.