A detailed study of self-assembled (Al,Ga)InP quantum dots grown by molecular beam epitaxy

We report on the structural and optical properties of self-assembled (Al,Ga)InP quantum dots (QDs) with varying material composition embedded in a (Al0.30Ga0.70)0.51In0.49P matrix. The samples were grown by gas-source molecular beam epitaxy. Atomic force microscopy was used to study the structural properties of the quantum dots, revealing a strong dependence of the morphology on the material composition. Low-temperature ensemble photoluminescence was observed between 590 nm and 720 nm. Temperature and excitation power dependent, as well as time resolved measurements were performed, indicating a significantly reduced electron confinement and a reduced overlap of the electron/hole wavefunctions for Al- and/or Ga-rich compositions