Valence and Conduction Band State Densities of Crystalline and Amorphous Ge as Seen via Photoelectron Spectroscopy

Photoemission energy distributions N(E,ω) were taken as a function of both electron energy E and photon energy ℏω using synchrotron radiation. Various spectral features associated with critical points in both the valence and conduction bands evident in crystalline Ge are absent in amorphous Ge. Features observed for amorphous Ge include: valence p‐bands about 4.2 eV wide with a peak at ∼ 1.4 eV below the valence band edge E_v, an overall valence bandwidth of ∼ 11.6 eV, and a conduction band state density peak at ∼ 2.3 eV above E_v.