Luminescent solar concentrators (LSCs) have proven to be highly effective in enhancing the conversion efficiency of photovoltaic (PV) cells. However, the traditional LSCs always suffer from self-absorption and escape the losses of luminescence. To these challenges, this study presents an ingenious all-wood-based LSC (W-LSC) with directional light-concentrating capabilities. By converting lignin into fluorescent carbon quantum dots (CQDs) and integrating them into transparent cellulose channels in delignified wood, we achieved efficient directional luminescence transmission in the W-LSC is achieved. The synthesized lignin-based CQDs (L-CQDs) exhibited a large Stokes shift (0.63 eV) and a bright yellow emission (540 nm). The prepared W-LSC possessed an external optical efficiency (ηopt) along the longitudinal (L) direction of 4.60% under a low irradiation intensity (40 mW·cm-2). Besides, contributed to the low thermal conductivity (0.300 W·m-1·K-1) of wood, the W-LSC maintained an ηopt of 4.03% at a temperature of 65 °C. Furthermore, the W-LSC demonstrated high tensile strength (424 MPa) and light transmission (85%). By leveraging the advantages of wood, this approach provides a different solution for enhancing solar energy utilization and advancing sustainable building.
Keywords: Stokes shift; carbon dots; directional light concentrating; lignin; luminescent solar concentrators; transparent wood.