Electrochromism induced reversible upconversion luminescence modulation of WO3:Yb3+, Er3+ inverse opals for optical storage application

Reversible modulated upconversion luminescence exhibits an application potential as the photo-switch, fingerprint acquisition, anti-counterfeiting and optical storage devices. It is found that the photochromism and thermochromism could be applied to modify the upconversion luminescence. However, the electrochromism induced reversible upconversion luminescence modulation was not reported. Here, the WO3:Yb3+, Er3+ inverse opal was prepared by the template approach, and its electrochromism property was investigated. The color changing of WO3:Yb3+, Er3+ inverse opal from a bit yellow to black was observed upon the negative bias voltage stimulation, and its color can be recovered upon the positive bias voltage stimulation. For the first time, the electrochromism induced reversible upconversion luminescence modulation of WO3:Yb3+, Er3+ inverse opal was observed, exhibiting a high modulation degree (100%). In addition, the reversibly modulated upconversion luminescence exhibited excellent repeatability and stability by alternating stimulation between negative bias voltage and positive bias voltage. The present results open up a new channel to modulate the upconversion luminescence of materials, exhibiting the application potential in the switch, anti-counterfeiting and optical storage devices. As an instance, the application potential of WO3:Yb3+, Er3+ inverse opal was described as an optical storage medium, and the optical date writing and reading out were obtained in the electrochromic WO3:Yb3+, Er3+ inverse opal.