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Highly efficient indoor light quasi-solid-state dye sensitized solar cells using cobalt polyethylene oxide-based printable electrolytes
摘要： High-performance printable electrolytes (PEs) containing Co+2/Co+3 or I-/I3- redox-couple are prepared to fabricate quasi-solid-state (QS) dye-sensitized solar cells (QS-DSSCs) for room light environment applications. Polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) are utilized to prepare PEs. Various parameters are regulated to obtain the optimal power conversion efficiencies (PCEs). For the I-/I3- system, the QS-DSSCs using PEO and PEO/PMMA PEs achieve nearly identical PCEs (16.32% and 16.40%, respectively) under the optimal conditions. However, the PCEs obtained for the Co+2/Co+3 system are markedly higher and the cell using PEO PE has a higher PCE (21.06%) than that using PEO/PMMA (18.14%). This difference is ascribed to the different composition of Li+ and Co+3 around the photoelectrode. The presence of Li+ around the interface will repel Co+3 away from the interface, decreasing the recombination of excited electrons to Co+3. According to the molecular structure, PMMA has more lone pair electrons to coordinate with Li+ ions, which will decrease the concentration of free Li+ more significantly than does by PEO. Therefore, the presence of PMMA will decrease and increase, respectively, the Li+ and Co+3 concentrations at the photoelectrode/electrolyte interface, resulting in more significant recombination of electrons to the Co+3. Consequently, the PCE of the PEO/PMMA cell is lower than that of the PEO cell. This effect doesn’t occur in I-/I3- system because the concentration variation of negatively charged ions did not affect significantly the electrons recombination at the interfacial. By using this cobalt PE, a bifacial QS-DSSC can achieve PCEs of 17.22% and 14.25%, respectively, under front-side and back-side illumination by 200 lux T5 light. A sub-module QS-DSSC using the cobalt PE can attain a PCE of 12.56%.
关键词： indoor light,sub-module cells,poly ethylene oxide,bi-facial cell,cobalt electrolyte,printable electrolyte
更新于2025-09-23 15:21:01
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Grafted PEO polymeric ionic liquid nanocomposite electrospun membrane for efficient and stable dye sensitized solar cell
摘要： An innovative polymeric ionic liquid (PIL) was synthesized by covalently grafting vinyl imidazolium iodide and methyl methacrylate onto poly (ethylene oxide) (PEO). Synthesised tungsten oxide nanoparticles (WO3NPs) were incorporated into the PIL solution and a polymer nanocomposite fibrous membrane (PVIM-W) was fabricated by electrospinning. This was used as a functional electrolyte for quasi solid state dye sensitized solar cell ((QSS-DSSC). The structure and morphology of the membranes and its physical characteristics as electrolytes were studied. The SEM images showed formation of uniform and beadless nanofibers. Photovoltaic and electrochemical effects of all the electrolytes have been examined. PVIM-W membrane exhibited superior power conversion efficiency (η) of 7.2% and better stability (up to 94.4% of its initial conversion efficiency after 500 h) when compared to the cell with the liquid electrolyte (η= 6.85%) and the ungrafted PEO membrane. This novel PVIM-W membrane based electrolyte shows great prospect for development of efficient and stable QSS-DSSC.
关键词： polymeric ionic liquid,poly (ethylene oxide),Dye sensitized solar cell,electrolyte,electrospun membrane
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Random Laser Action from Electrospun Polymeric Nanofibers Doped Either with Organic Dye or Semiconductor Nanoprisms
摘要： The search for light sources with targeted characteristics motivates the work of a large part of the photonics community. One topical subject in this area is the study of Random Lasers (RLs), which use as feedback mechanism the light scattering in a random medium instead of a Fabry-Perot cavity. A large variety of RLs and a diversity of applications have already been demonstrated. Of interest in many applications are RLs based on flexible hosts, which act not only as mechanical support, but also as scattering agent. Such host can be obtained, for example, by electrospinning fibers made by environment-friendly materials. In this work, we report on a technique to produce a system composed by electrospun acetate ester of cellulose nanofibers (AEC-NFs) containing poly(ethylene oxide) – PEO (10% or 20% wt. - known to improve the mechanical properties of AEC-NFs), which presence originates a double-peaked diameter distribution centred around 120 nm and 600 nm. RL experiments were made with either Rhodamine 6G (Rh6G, 2 mM) or 40% wt. ZnO nanoprisms (NPs), that act as gain media. By varying the PEO amount in the AEC-NFs we investigate how the structures with smaller diameters act as scatterers for obtaining RL emission. Raman spectroscopy was performed in order to assure that PEO has been incorporated to the AEC-NFs in the desired amount.
关键词： poly(ethylene oxide),Rhodamine 6G,Random Lasers,ZnO nanoprisms,electrospun nanofibers
更新于2025-09-11 14:15:04
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High performance perovskites solar cells by hybrid perovskites co-crystallized with poly(ethylene oxide)
摘要： Hybrid perovskite materials have emerged as attractive alternatives for cost-effective solar cells in the past ten years. However, achieving hysteresis-free, stable and efficient solution-processed perovskites solar cells has remained as a significant fundamental challenge. In this study, we report a strategy that utilizes poly(ethylene oxide) to sequester the counter ions in the perovskite lattices to suppress the formation of point defects, reduce the migration of ions/vacancy and to facilitate crystal growth in a more thermodynamically preferred orientation. Systematical investigations indicate that poly(ethylene oxide) indeed form hydrogen bonds with perovskite, which reduces the formation of kinetically-driven point defects, minimize charge carrier recombination and sharpen the density of states distribution. As a result, un-encapsulated solution-processed perovskite solar cells exhibit stabilized power conversion efficiency with hysteresis-free characteristics and significantly improved ambient shelf- and thermal-stability at relative high humidity, in comparison to the reference devices that exhibit unstable power conversion efficiency with dramatically higher hysteresis factor and poorer device lifetime. Our studies demonstrate that development of hybrid perovskite materials co-crystallized with polymers is an efficient approach towards high performance perovskite solar cells.
关键词： photocurrent hysteresis,hydrogen bonding,stability,poly(ethylene oxide),power conversion efficiency,hybrid perovskite
更新于2025-09-11 14:15:04