Facile patterning of upconversion NaYF4:Yb, Er nanoparticles

► We firstly using a simple method combining micro-contact printing and “breath figures” techniques to fabricate a near-infrared imaging photographic films. ► The self-assembly process may give important insights into fluid-fluid interfacial phenomena. ► These ordered 2D films may also be potentially useful as new templates to prepare multifunctional patterns. ► The different pattern of the film is great significant. It can be utilized as IR sensor, camera photographic film and so on.