Study on vacuum ultraviolet spectra of amorphous Er2O3 films on Si(001) substrates

Abstract Amorphous Er 2 O 3 films have been fabricated on p-type Si(001) substrates using radio frequency magnetron sputtering technique. Vacuum ultraviolet spectra were employed to investigate the samples. An optical gap of 6.17 eV for Er 2 O 3 films was obtained from the absorption coefficient spectra. A possible reason was put forward to explain the inconsistent results about the band gap of Er 2 O 3 in literatures. Emission spectra exhibited a strong emission band at 494 nm with the incident ultraviolet light of 249 nm. The observed high density of emission bands of Er 2 O 3 films in the visible wavelength indicated that Er 2 O 3 films could be used in Si solar cells for increasing conversion efficiency.