Photon upconversion with directed emission
Journal article, 2016

Photon upconversion has the potential to increase the efficiency of single bandgap solar cells beyond the Shockley Queisser limit. Efficient light management is an important point in this context. Here we demonstrate that the direction of upconverted emission can be controlled in a reversible way, by embedding anthracene derivatives together with palladium porphyrin in a liquid crystalline matrix. The system is employed in a triplet-triplet annihilation photon upconversion scheme demonstrating controlled switching of directional anti Stokes emission. Using this approach an emission ratio of 0.37 between the axial and longitudinal emission directions and a directivity of 1.52 is achieved, reasonably close to the theoretical maximal value of 2 obtained from a perfectly oriented sample. The system can be switched for multiple cycles without any visible degradation and the speed of switching is only limited by the intrinsic rate of alignment of the liquid crystalline matrix.

Author

Karl Börjesson

University of Gothenburg

Per Rudquist

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Victor Gray

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Polymer Technology

Kasper Moth-Poulsen

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Polymer Technology

Nature Communications

2041-1723 (ISSN)

Vol. 7 artikel nr 12689- 12689

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Energy

Materials Science

Subject Categories

Physical Chemistry

Atom and Molecular Physics and Optics

Materials Chemistry

Chemical Sciences

Infrastructure

Chalmers Infrastructure for Mass spectrometry

Chalmers Materials Analysis Laboratory

DOI

10.1038/ncomms12689

More information

Latest update

5/17/2018