Consonant diminution of lattice and electronic coupling between a film and a substrate: Pb on Ge(100)

The dependence on thickness of electronic and lattice structures of Pb films deposited on Ge(100) substrate was investigated with angle-resolved photoemission spectroscopy and low-energy electron diffraction. Pb films grew in the (111) surface direction with two (1 × 1) domains rotated 90° relative to each other despite a square lattice of Ge(100); correspondingly, the heavy-hole band edge of Ge does not interact with quantum-well-state bands of Pb films. Symmetry arguments in terms of orbitals of Pb quantum-well states and Ge band edges correlate the consonant diminution of lattice and electronic coupling between the film and the substrate.