Kinetic influences on void formation in epitaxially regrown GaAs-Based PCSELs

We report an investigation into the formation of crystallographic voids during metalorganic vapour phase epitaxial regrowth GaAs photonic crystal structures. employ a combination cross-sectional scanning electron microscopy and transmission to study structures regrown with AlAs, AlGaAs GaAs. The change in material allows effect adatom diffusion kinetics on void structure be assessed. Whilst complete grating infill is observed for GaAs, promoted Al-containing materials, size increasing Al mole fraction, line reduced mobility. In case both AlAs AlGaAs-regrown structures, degree asymmetry shape within plane crystal. These differences are attributed variations group-III surface mobility polarities high-index planes along orthogonal directions. Two growth regimes stable dynamic faceting cross-sections containing A- B-type polarities, respectively.