Metal-semiconductor Nano-composite Material as seen in Cross-section in an Electron Microscope Image
D. Klenov, D. Driscoll, M. Hanson, S. Stemmer and A.C. Gossard

Dark-colored lines are layers of metal islands (erbium arsenide) in a semiconductor (indium gallium arsenide). The unique honeycomb structure occurs with alternate growth of ErAs and InGaAs by molecular beam epitaxy. The metal islands form in a spontaneous island mode of crystal growth. Faceting of the surface and appearance of the honeycomb structure occur only for metal depositions and indium content greater than a certain level.