title: Delayed onset of photochromism in molybdenum oxide films caused by photoinduced defect formation.
abstract: We report the photochromic properties of amorphous MoO3films deposited by dc sputtering with different O2flow rates. The kinetics of film coloration under UV light irradiation is determined using optical transmission spectroscopy. Changes in the absorbance and refractive index were derived from the analysis of transmittance spectra. The absorbance spectra exhibited a growing broad peak centered around 830 nm, which was induced by the UV irradiation. In the early stages of irradiation, the absorbance of the films did not change but their refractive indices did change. This induction time was correlated with the O2partial pressure during the film deposition, which was controlled by the O2flow rate. The origins of this observation are discussed.
authors.affiliation: Institute of Materials Research and Engineering, IMRE, Agency for Science Technology and Research (A-STAR) 3 Research Link, Singapore, 117602, Singapore.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Rouhani
authors.affiliation: Institute of Materials Research and Engineering, IMRE, Agency for Science Technology and Research (A-STAR) 3 Research Link, Singapore, 117602, Singapore.
authors.forename: Sergey
authors.initials: S
authors.lastname: Gorelik
authors.affiliation: Institute of Materials Research and Engineering, IMRE, Agency for Science Technology and Research (A-STAR) 3 Research Link, Singapore, 117602, Singapore.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hobley
authors.affiliation: Institute of Materials Research and Engineering, IMRE, Agency for Science Technology and Research (A-STAR) 3 Research Link, Singapore, 117602, Singapore.
authors.forename: Shi Jie
authors.initials: SJ
authors.lastname: Wang
authors.affiliation: Institute of Materials Research and Engineering, IMRE, Agency for Science Technology and Research (A-STAR) 3 Research Link, Singapore, 117602, Singapore.
authors.forename: Evan Laurence
authors.initials: EL
authors.lastname: Williams
authors.affiliation: Institute of Materials Research and Engineering, IMRE, Agency for Science Technology and Research (A-STAR) 3 Research Link, Singapore, 117602, Singapore.
authors.forename: Yong Lim
authors.initials: YL
authors.lastname: Foo
keywords: absorption coefficient; molybdenum oxide; oxygen vacancy; photochromism; refractive index; thin film