Lignin Nanoparticles: Promising Sustainable Building Blocks of Photoluminescent and Haze Films for Improving Efficiency of Solar Cells

Abstract

Films with the capacity for photoluminescence and haze, which can convert UV to visible light and enhance light management, are of great importance for optoelectronic devices. Here, taking advantage of the inherent fluorescence and self-assembly properties of lignin, we have developed a sustainable lignin-derived multifunctional dopant (L-MS-NPs) for fabricating optical films with haze, fluorescence, and room-temperature phosphorescence (RTP) together with poly­(vinyl alcohol) (PVA). The optical films are used to improve the light-harvesting efficiency of solar cells. Specifically, attributed to the robust morphology in the film matrix, L-MS-NPs cause a rough morphology in the surface of an L-MS-NPs/PVA composite film, which eventually triggers the great optical haze. Additionally, L-MS-NPs inherit fluorescence properties from lignin and show fluorescence emission when embed in the film matrix. Moreover, the PVA film matrix can stabilize the excited triplet state, which finally induces RTP of L-MS-NPs. The combined haze, fluorescence, and RTP properties of the L-MS-NPs/PVA composite film enhances the power conversion efficiency (PCE) of dye-sensitized solar cells from ∼3.9 to ∼4.1%.

Effect of the Performance of Lignin Into the Matrix of the TiO2 with Application on DSSCs

“…Figure 1 illustrates the spectrum of optical absorbance of the films of TiO 2 and TiO 2 /lignin (EST5LG -5%, EST10LG -10%, EST15LG -15%) after dyeing for 24 h with the N719. The range where there is the luminous energy into electricity conversion corresponds to the 400-700 nm intervals, on the visible range of the solar spectrum (Wang X et al, 2021). And, facing the results indicated in the spectrum of the 15% lignin sample (EST15LG) in the TiO 2 matrix, this sample was the one with higher optical absorption in the visible range, with a peak at 522 nm.…”

“…This higher absorption may have happened due to the thicker structure of the films and higher dye adsorption on the TiO 2 /lignin thin surface, with a possible lower band gap. And, the introduction of the dopant elements in the TiO 2 structure is one of the strategies to modify the photoanodes to increase the photons capture to favor better efficiency of luminous energy into electricity conversion in DSSCs (O'Regan B and Grätzel M, 1991;Wang X et al, 2021;Matthews D et al, 1996;Kumari JMKW et al, 2016). After the optical analyses of the films (Figure 1), it is possible to infer that the 15% lignin film (EST15LG) in the TiO 2 matrix had the better performance in the optical characterization.…”

Cellulose-Based Fluorescent Material for Extreme pH Sensing and Smart Printing Applications

“…In addition, haze properties of films are an important parameter which indicate the difference of incident light to that of scattered light and reveal promising food packaging, photovoltaic, and solar cell applications. , Therefore, haze properties of polymer blend films were investigated (Figure S16C). As can be seen, the 1 and 5% CA-blended films demonstrate significant transparency; however, the films display excellent haze characteristics under visible light at 1 cm distance.…”

Efficient and selective removal of Pb(ii) from aqueous solution by a thioether-functionalized lignin-based magnetic adsorbent

“…As presented in Scheme 1 , the lignin-based magnetic adsorbent (L@MNP) was fabricated from sulfhydryl-functionalized SMNP and alkenyl lignin via the thiol–ene click reaction under UV light (365 nm) irradiation. 32 It was expected that the lignin layer coated on the L@MNP surface would enhance the dispersibility and stability of the magnetic core and simultaneously facilitate its adsorption performance due to the generation of thioether bonds (C–S) as adsorbing sites. 33 …”