Conduction Band Discontinuity in n-type Si/TiO2 Heterojunction Interfaces. (25th January 2021)

• Record Type: Journal Article
• Authors: Kavaliunas, Vytautas; Hatanaka, Yoshinori; Neo, Yoichiro; Laukaitis, Giedrius; Mimura, Hidenori
• Is Part Of: ECS journal of solid state science and technology. Volume 10:Number 1(2021)
• Publication Date: 2021-01-25
• Subjects: TiO2 -- n-type Si -- Heterojunction -- Conduction band; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2162-8777/abdc49
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : The conduction band discontinuity between n-type Si substrates and anatase TiO2 films has been investigated. n-type Si substrates with three different dopant concentrations were used as a substrate for TiO2 thin-films: ND = 10 15–16 cm −3 (as n-Si); ND = 10 17–18 cm −3 (as n + -Si); ND = 10 20–21 cm −3 (as n ++ -Si). The translation of X-ray photoelectron spectroscopy (XPS) results to an energy band diagram through the valence band offset (VBO) enables us to evaluate the conduction band discontinuities accurately: n-Si/TiO2 —−0.22 eV, n + -Si/TiO2 —−0.06 eV, and n ++ -Si/TiO2 —+0.07 eV. Temperature–dependent current–voltage (I–V) characteristics were measured to evaluate the Fermi energy level (EF ) of the TiO2 thin-films. Light transmittance was measured to evaluate the energy bandgap of the TiO2 thin-films. The band diagram of the n-type Si/TiO2 heterojunction was proposed. Deep-insight analysis of n-type Si/TiO2 was carried out on the basis of measured I–V characteristics.