Novel Quasi-Solid-State Electrolytes based on Electrospun Poly(vinylidene fluoride) Fiber Membranes for Highly Efficient and Stable Dye-Sensitized Solar Cells

Abstract

To obtain new highly efficient and stable quasi-solid dye-sensitized solar cells (QS-DSSCs) that can meet the requirements for the large-scale commercial application of solar cells, we have developed a novel quasi-solid-state electrolyte, based on an electrospun polyvinylidene fluoride (PVDF) membrane. The structure and properties of electrospun PVDF membranes were characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), thermogravimetric (TG), and mechanical testing. The results indicate that the electrospun PVDF membrane has a three-dimensional network structure with extremely high porosity, which not only acts as a barrier to prevent electrolyte leakage but also provides a channel for the transmission of ions in the electrolyte, thereby effectively guaranteeing the high photoelectric conversion efficiency of the cells. The membrane was observed to withstand the conditions of hot-press (110 °C), and exhibited good thermal stability and mechanical strength, which are critical for the long-term stability and safety of the cells. The photovoltaic characteristics and stabilities of QS-DSSCs were compared with DSSCs based on an ionic liquid electrolyte (L-DSSC). QS-DSSCs with an 80 μm thick nanofiber electrolyte membrane showed a conversion efficiency of 8.63%, whereas an identical cell based on the corresponding ionic liquid electrolyte showed an efficiency of 9.30%. The stability test showed that, under indoor and outdoor conditions, after 390 h, the L-DSSCs failed. Meanwhile, the QS-DSSCs also maintained 84% and 77% of the original efficiency. The results show that, compared to the liquid electrolyte, the design of the quasi-solid electrolytes based on electrospun PVDF nanofiber membrane not only demonstrates the high conversion efficiency of DSSCs but also enhances the stability of the DSSCs, which provides the possibility for the fabrication of solar cells with higher efficiency and stability.

Photovoltaic Performance of Dye-Sensitized Solar Cells Containing ZnO Microrods

“…To confirm this, we conducted EIS measurements. EIS is a powerful tool for investigating the charge transport kinetics and the charge recombination in DSSCs [22][23][24][25]. The results measured at −0.7 V in the dark are shown in Figure S2 in the Supplementary Information section.…”

“…The Nyquist plots of the EIS spectra for the DSSCs are presented in Figure 6b. The Nyquist plots typically include three semicircles: the first semicircle (R 1 ) corresponds to the redox reaction at the Pt counter electrode, the second one (R 2 ) corresponds to the electron transfer at the ZnO/dye/electrolyte interface, and the third one (R 1 ) corresponds to the carrier transport by ions in the electrolytes [24][25][26]. It was noted that by the extended growth time the impedance component of R 2 in the medium-frequency region was increased.…”

Solar Cells for Indoor Applications: Progress and Development

“…The chemical structures of some dyes are depicted in Figure 6 Wen et al fabricated and utilized a polyvinylidene-fluoride-based quasi-solid electrolyte for an N719-dye-based DSSC. Their device exhibited better stability than a liquid-electrolyte-based DSSC for both indoor and outdoor conditions [90]. In 2017, Chang and Chi prepared a Ru-based new dye sensitizer TF-tBu-C3F7 [76].…”

Investigating Various Permutations of Copper Iodide/FeCu Tandem Materials as Electrodes for Dye-Sensitized Solar Cells with a Natural Dye

“…Another study on the modification of the DSSC by Li et al showed the use of ZnO hollow microspheres coated by TiO 2 in Quantum Dots DSSC to enhance the light harvesting efficiency of the cell, resulting in a power conversion efficiency of 3.16% compared to 1.54% in the absence of the TiO 2 coating [7]. Moreover, in their attempt at commercializing DSSC, Cheng et al reported the development of a quasi-solid DSSC with a long-term stability with a conversion efficiency of 8.63% [8]. In addition, due to intensive research, the efficiency of the DSSC reached a record value of 14.30% in 2015 [9].…”