Formation Of InAs/InGaAsP Quantum Dashes

Self‐assembled InAs/InGaAsP/InP(001) nanostructures are investigated using cross‐sectional scanning tunneling microscopy. Atomically resolved images show elongated nanostructures with binary composition and a truncated pyramidal shape. The investigation of the InGaAsP/InP interface shows a tendency of the quaternary matrix material towards decomposition and indicates InAs quantum‐dash formation by nucleation on initially slightly decomposed InAs‐rich regions of the InGaAsP.