ELECTROREFLECTANCE OF DISORDERED GERMANIUM FILMS

The transition from the crystalline to the amorphous state has been studied in germanium thin films by observing the electroreflectance spectra related to critical points at Γ(E0, E0+Δ0), along the Λ direction (E1, E1+Δ1), and at areas with Δ and symmetry (E2). A small shift of E0 to lower energy with increasing disorder in the crystalline state, and weak structure in the amorphous state, have been observed. The spectral positions of E1, E1+Δ1 and E2 do not change with disorder in the crystalline state but these responses are completely absent in the amorphous state. © 1969 The American Physical Society.