Transparent Polylactic Acid Fiber Doped with Photoluminescent Dyes for Luminescent Solar Concentrators

Transparent polylactic acid (PLA) fibers with Lumogen Red 305 (LR305) were prepared by melt spinning. The crystallization and melting behavior, absorbance spectra, emission spectra, mechanical properties, and the concentrator effect for a real solar cell of the PLA/LR305 fibers were characterized by differential scanning calorimetry (DSC), UV–Vis–NIR spectrophotometer, FL spectrophotometer, yarn tensile tester, and a digital multimeter (Victor VC980 + ), respectively. The results showed that the hot drawing improves the mechanical properties of the fibers while maintaining the optical properties. When the concentration of LR305 was 0.05 wt%, the breaking strength of the stretched fiber 22@217 (22% crystallinity, 217 diameters) and the as-formed fiber 3@205 (3% crystallinity, 205 diameters) were 69.3 and 182.7 MPa, respectively. Meanwhile, the absorbance intensity and luminescence intensity of 22@217 decreased only 6 and 11% compared with 3@205. When triple-drafted PLA/LR305 fibers with a concentration of 0.25 wt% were combined with the solar cell, the solar cell output current changed from 0 to 2.8 μA.