Enhanced photoconductivity in nitrogen-doped amorphous silicon prepared by d.c. sputtering

Amorphous silicon, prepared by d.c. sputtering in a hydrogen/argon mixture, has been obtained with a low dark conductivity (10 −10 Ω 1 cm −1 ) at room temperature and a high photoconductivity. Moreover, a high-level doping has been achieved by the introduction of nitrogen in the plasma during the sputtering process. This doping displaces the Fermi level to within 0.1 eV of the conduction band edge and enhances the photoconductivity by several orders of magnitude.