Luminescent solar concentrators: Nanorods and raytrace modeling

Nanorods are a novel and promising component for luminescent solar concentrators (LSCs). In particular, their spectra suggest reduced re-absorption losses. We report the incorporation of core-shell nanorods in homogeneous and thin film LSCs. The rods in the solid host appear to retain their spectral features compared to their dissolved state. Short-circuit current measurements with a calibrated solar cell have been compared with the computational simulation of the LSCs. Our raytrace model was applied to fit the fundamental emission spectrum and extract the quantum efficiency (QE) of the nanorods in the concentrators. In the case of the homogeneous LSC, the extracted QE was (67±4)%, which is in good agreement with the quoted value of about 70% for rods in solution. The thin film samples showed noticeably worse performance, which was attributed to possible agglomeration of rods and to macroscopic defects in the film. Finally, the raytrace model was applied to compare the self-absorption between a typical quantum dot concentrator and a nanorod concentrator. The result supported the argument that nanorods exhibit a smaller spectral overlap and consequently less re-absorption losses.