title: Inkjet printing of upconversion nanoparticles for anti-counterfeit applications.
abstract: Patterning of upconversion luminescent materials has been widely used for anti-counterfeit and security applications, where the preferred method should be easy, fast, multicolor, high-throughput and designable. However, conventional patterning methods are complex and inflexible. Here, we report a digital and flexible inkjet printing based approach for producing high-resolution and high-luminescence anti-counterfeit patterns. We successfully printed different multicolor luminescent patterns by inkjet printing of upconversion nanoparticles with controlled and uniform luminescence intensity through optimizing the inks and substrates. Combined with another downconversion luminescent material, we achieved two different patterns in the same area, which show up separately under excitation by different wavelength laser sources. The developed technology is promising to use one single substrate for carrying abundant information by printing multilayer patterns composed of luminescent materials with different excitation light sources.
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P.R. China. fengxu@mail.xjtu.edu.cn.
authors.forename: Minli
authors.initials: M
authors.lastname: You
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Hong
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Duan
authors.forename: Min
authors.initials: M
authors.lastname: Lin
authors.forename: Feng
authors.initials: F
authors.lastname: Xu