Stokes shift leads to significant overlap of its absorption and emission spectra (see Figure ), meaning reabsorption losses are common in LR305-based LSCs. PMMA satisfies most of the requirements required to minimize waveguide losses, namely a refractive index ~1.49, good optical clarity, and high transmittance across a large portion of the solar spectrum. Key examples from the literature reporting the efficiency of square LR305-PMMA LSCs were selected to compare the ability of pvTrace-v2.1.sv to predict the external photon efficiency.