Figure 11

Schematics of band structures of the Si p–i–n -diodes with Ge QD arrays represented in Figure 1. (a) R 163, (b) R 166; figures ‘1’, arrows and wavy lines indicate potential barriers for holes in the valence band (_{E v}) which are associated with the Ge QD arrays; black and shaded parts of potential wells show bands of filled (above the Fermi level F) and empty (below F) energy levels in the QD ensemble; two vertical wavy lines in panel (b) indicate a gap in the drawing of a very thick buffer layer of Si (1690 nm) deposited on the n-Si substrate.