Effect on the output of a luminescent solar concentrator on application of organic wavelength-selective mirrors

Abstract

To reduce surface loss in luminescent solar concentrators (LSCs), we systematically apply organic wavelength-selective mirrors, chiral nematic (cholesteric) liquid crystals, onto the LSCs with an air gap and determine their effect on waveguide output. The highest output is achieved using a scattering background and cholesteric mirror with a reflection band significantly redshifted ($\sim 150\mathrm{nm}$) from the emission peak of the fluorescent dye. The use of an air gap results in light bending away from the wave guide surface normal and, consequently, a redshift of the cholesteric mirrors is required. Up to 35% more dye-emitted light energy exits the waveguide edge after application of the cholesteric, and an increase in absolute edge power of 12% was found for a waveguide using a separate scatterer.