Urbach tail in amorphous gallium arsenide films

摘要: Measurements using photothermal deflection spectroscopy (PDS) have been performed on samples of amorphous gallium arsenide deposited by rf sputtering monocrystalline GaAs targets with and without hydrogen. The trend the Urbach energy, E 0 , Tauc gap, g as a function some deposition parameters is discussed. In particular, behavior shows decrease quantity ( W / p ) 1/2 where discharge power pressure chamber. increases hydrogen tends to saturate when H 2 greater than 0.1 Pa. exactly opposite trend.