Highly Efficient, Bio-compatible and Three-Dimensional Solid Phase Upconversion Hosting Material

Triplet-triplet annihilation based upconversion (TTA-UC), the special photochemical process of converting two or more photons of lower energy into one photon of higher energy in multichromophore systems, has attracted much attention due to its potential in various applications including solar-based technologies and biophotonic application as well. Despite these advantages of TTA-UC, the development of effective UC host material for practical devices has been difficult due to the prerequisite for TTA-UC such as high diffusivity and anoxic conditions. This research reports a new TTA-UC host material: polycaprolactone (PCL) and polylactic acid (PLA) polymer blends for highly efficient, processible, and bio-compatible solid-phase TTA-UC. The photochemical properties of the prepared TTA-UC sample were fully characterized and fabrication of three-dimensional upconverting architecture using commercially available 3D-printer was demonstrated for the first time.