Absence of thermal quenching effects in undoped amorphous silicon deposited by the pecvd of he - diluted silane

The effect of thermal quenching on the optoelectronic properties of well characterized undoped rf glow discharge amorphous silicon deposited under standard conditions and from silane helium mixtures has been studied. The defect density of the "helium diluted" samples is shown to be independent of the temperature up to 300°C; this could be a sign of a better stability of these films. The data are analyzed in terms of recent equilibrium models and discussed in relation with hydrogen-related properties resulting from the particular growth conditions.