Annihilation assisted upconversion: all-organic, flexible and transparent multicolour display

In this paper, we demonstrate the first all-organic, transparent, flexible, versatile colour displays based upon triplet-triplet annihilation assisted photon energy upconversion in viscous polymeric matrix. The devices work with ultra-low excitation intensities down to 20 mW cm-2 red or near-IR light. The displays are based on metallated-porphyrin sensitizers in combination with emitters dispersed in a transparent polymeric matrix and are driven by galvo-scanned laser diodes. The displays have external quantum yield as high as 3.2%. The response time can be adjusted to specific application requirements-up to 80 μs allowing kHz-refreshment rate of the displayed information. It is possible to easily tune the optical density of the screens in order to obtain a desired transmittance for the excitation beam. We demonstrate the ability to achieve multicolour emission, using only one excitation source. There are practically no display size limitations.