title: Schottky barrier characteristics and internal gain mechanism of TiO2 UV detectors.
abstract: High-responsivity metal-semiconductor-metal TiO(2) UV photodetectors with Ni and Au electrodes were fabricated identically. Their Schottky barrier heights and photocurrent gain mechanism were studied. The effective barrier height Φ and ideality factor n were evaluated according to the thermionic emission theory. The result that Φ(Ni) was lower than Φ(Au) may be attributed to the electron transfer from Ni to the TiO(2) substrate, which would lead to a dipole layer and, accordingly, decrease the barrier height. In addition, the I-V characteristics of the Ni/TiO(2)/Ni and Au/TiO(2)/Au photodetectors were observed. A significant internal gain was obtained, and the mechanism of the internal gain was studied by the phototransistor model in detail.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, Jilin University, 2699 Qianjin Street, Changchun 130012, China. wolfzhang2007@163.com
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Caihui
authors.initials: C
authors.lastname: Feng
authors.forename: Weiyou
authors.initials: W
authors.lastname: Chen
authors.forename: Caixia
authors.initials: C
authors.lastname: Liu
authors.forename: Jingran
authors.initials: J
authors.lastname: Zhou
authors.forename: Shengping
authors.initials: S
authors.lastname: Ruan