Measurements using photothermal deflection spectroscopy (PDS) have been performed on samples of amorphous gallium arsenide (a-GaAs) deposited by rf sputtering. Small quantities of hydrogen (p(H2)=1% P-Ar) induce changes of the Urbach energy, E(0). This quantity has a linear relation with the Tauc optical gap, E(g). The behaviour of E(0) shows a decrease as a function of the quantity (W/p)(1/2), where W is the discharge power and p the pressure in the deposition chamber. E(g) increases with the hydrogen pressure and tends to saturate when p(H2) is greater than 0.1 Pa. E(0) shows exactly the opposite trend. These results are related to structural and morphological data obtained by TEM and THEED measurements.
Optical properties of amorphous gallium arsenide films.
PINTO, Nicola;MURRI, Roberto Vittorio
1993-01-01
Abstract
Measurements using photothermal deflection spectroscopy (PDS) have been performed on samples of amorphous gallium arsenide (a-GaAs) deposited by rf sputtering. Small quantities of hydrogen (p(H2)=1% P-Ar) induce changes of the Urbach energy, E(0). This quantity has a linear relation with the Tauc optical gap, E(g). The behaviour of E(0) shows a decrease as a function of the quantity (W/p)(1/2), where W is the discharge power and p the pressure in the deposition chamber. E(g) increases with the hydrogen pressure and tends to saturate when p(H2) is greater than 0.1 Pa. E(0) shows exactly the opposite trend. These results are related to structural and morphological data obtained by TEM and THEED measurements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
