Effect of metal seed layer on the critical thickness and photoelectric properties of ultrathin Ag films

Abstract

To decrease the critical thickness for Ag to form a continuous film and improve the photoelectric properties of the transparent conductive film, the metal seed layer was introduced as a wetting layer, and the metal seed/Ag/AZO composite film was prepared on K9 glass substrates by the magnetron sputtering equipment. The effects of the metal seed layer on both the critical thickness of continuous Ag layer and the photoelectric properties of composite film were investigated. The Al seed layer reduces the critical thickness of the Ag layer to 10 nm, and the square resistance of the Al/Ag (10 nm)/AZO composite film decreases by 5.53 Ω/sq compared to the Ag(10 nm)/AZO bilayer film, while its average transmittance of visible light (380–780 nm) increases by 2.33 %. The Cu seed layer further reduces the critical thickness of the Ag film to 8 nm, and the square resistance of the Cu/Ag(8 nm)/AZO composite film decreases to 9.26 Ω/sq, of which average visible light transmittance reaches 69.34 %. The square resistance of the Cu/Ag (10 nm)/AZO composite film is as low as 7.43 Ω/sq, which is 8.48 Ω/sq lower than that of the Ag (10 nm)/AZO bilayer film.