Impact of Bi incorporation on the evolution of microstructure during growth of low-Temperature GaAs:Bi/Ga(As,Bi) layers
Research output: Contribution to journal › Article › Scientific › peer-review
|Journal||Journal of Applied Physics|
|Publication status||Published - 28 Aug 2019|
|Publication type||A1 Journal article-refereed|
Complex morphology is observed in the GaAs:Bi cap layer of Ga(As,Bi) films grown on GaAs(001) substrates by low-Temperature (LT) molecular beam epitaxy (MBE). The microstructure is dominated by the presence of V-shaped domains in the LT-GaAs cap layer and by the (unintentional) inhomogeneous incorporation of Bi from the underlying Ga(As,Bi) layer growth. Aberration-corrected scanning transmission electron microscopy techniques enabled two types of domain to be identified: (i) twinned domains and (ii) Bi-rich atomically ordered domains with triple periodicity. The observed microstructure is discussed in the context of LT-MBE growth in combination with the presence of a small amount of Bi, which seemingly alters adatom diffusivity. Surface processes and (surface) kinetic factors play a key role in the resultant morphology and explain the appearance of both types of domains.