Sputtering deposition of transparent conductive F-doped SnO2 (FTO) thin films in hydrogen-containing atmosphere. Issue 13 (September 2017)

• Record Type: Journal Article
• Authors: Zhu, B.L.; Liu, F.; Li, K.; Lv, K.; Wu, J.; Gan, Z.H.; Liu, J.; Zeng, D.W.; Xie, C.S.
• Is Part Of: Ceramics international. Volume 43:Issue 13(2017)
• Page Start: 10288
• Page End: 10298
• Publication Date: 2017-09
• Subjects: Sputtering -- F-doped SnO2 (FTO) films -- H doping -- H2/Ar flow ratio -- Substrate temperature -- Base pressure; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.05.058
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: F-doped SnO2 (FTO) thin films have been prepared by sputtering SnO2 -SnF2 target in Ar+H2 atmosphere. The effects of H2 /Ar flow ratio on the structural, electrical and optical properties of the films were investigated at two substrate temperatures of 150 and 300 °C and two base pressures of 3.5×10 −3 and 1.5×10 −2 Pa. The results show that introducing H2 into sputtering atmosphere can lead to the formation of a FTO film with a (101) preferred orientation and produce oxygen vacancy ( V O ) at lower H2 /Ar flow ratios, but SnO phase at higher H2 /Ar flow ratios in the films. Accordingly, the resistivity of the films first decreases and then increases, but the transmittance decreases continuously with increasing H2 /Ar flow ratio. When H2 /Ar flow ratio is increased above a certain value, more amorphous SnO phase forms in the films, resulting in a big decrease in conductivity, transmittance, and band gap ( E g ). Increasing substrate temperature can increase the Hall mobility due to the improvement of film crystallinity, but decrease the carrier concentration due to outward-diffusion of fluorine in the films. At a base pressure of 3.5×10 −3 Pa, high substrate temperature (300 °C) can hinder the formation of SnO and thus improve the transparent conductive properties of the films. At a base pressure of 1.5×10 −2 Pa, the range of H2 /Ar flow ratio for forming the SnO2 phase and hence for obtaining high transparent conductive FTO films is widened at both substrate temperatures of 150 and 300 °C.