Nanodroplet-Containing Polymers for Efficient Low-Power Light Upconversion.

Nanodroplet-Containing Polymers for Efficient Low-Power Light Upconversion. Adv Mater. 2017 Sep 12;: Authors: Vadrucci R, Monguzzi A, Saenz F, Wilts BD, Simon YC, Weder C Abstract Sensitized triplet-triplet-annihilation-based photon upconversion (TTA-UC) permits the conversion of light into radiation of higher energy and involves a sequence of photophysical processes between two dyes. In contrast to other upconversion schemes, TTA-UC allows the frequency shifting of low-intensity light, which makes it particularly suitable for solar-energy harvesting technologies. High upconversion yields can be observed for low viscosity solutions of dyes; but, in solid materials, which are better suited for integration in devices, the process is usually less efficient. Here, it is shown that this problem can be solved by using transparent nanodroplet-containing polymers that consist of a continuous polymer matrix and a dispersed liquid phase containing the upconverting dyes. These materials can be accessed by a simple one-step procedure that involves the free-radical polymerization of a microemulsion of hydrophilic monomers, a lipophilic solvent, the upconverting dyes, and a surfactant. Several glassy and rubbery materials are explored and a range of dyes that enable TTA-UC in different spectral regions are utilized. The materials display upconversion efficiencies of up to ≈15%, approaching the performance of optimized oxygen-free reference solut...
Source: Adv Data - Category: Epidemiology Authors: Tags: Adv Mater Source Type: research