Increased mc-Si Module Efficiency Using Fluorescent Organic Dyes: A Ray-Tracing Study

Ray tracing is used to determine how the inclusion of BASF\´s fluorescent organic dyes might benefit a multi-crystalline silicon module. These dyes absorb short-wavelength photons and re-emit them at wavelengths that are longer and more favourable to the module. This down-shifting prevents many photons from being absorbed by the ethylene vinyl acetate (EVA) encapsulant, the cells\´ antireflective coating, and the "dead layer" of the cells\´ emitter. We find that under one-sun AM1.5g illumination, the inclusion of organic dyes might raise the short-circuit current density by as much as 0.7 mA/cm², which equates to an efficiency boost of 0.3% absolute. A further increase of 0.1 mA/cm² is attained by thickening the antireflective coating so that it is optimised for the new spectrum. It is shown that the incorporation of fluorescent dyes slightly increases the optimal emitter doping of the solar cells