Synthesis of Crosslinked Hydroxypropyl Methylcellulose with Methyl Gallate‐Poly(Ethylene Glycol) as a Gel Electrolyte for Dye‐Sensitized Solar Cells

Abstract

Hydroxypropyl methylcellulose (HPMC) is blended with methyl gallate (MG) encapsulated with poly(ethylene glycol) (PEG) and then mixed with a liquid electrolyte to prepare a polymer gel electrolyte. The structural and physical properties of prepared polymer gels are analyzed by various analytical instruments. The MG‐PEG‐HPMC hybrid is found to be able for entrapping a large amount of liquid electrolyte and is used to fabricate dye‐sensitized solar cells (DSSCs). This polymer gel electrolyte shows high ionic conductivity (5.43 × 10−4 S cm−1) and good triiodide diffusion coefficient (2.25 × 10−6 cm2 s−1). The resulting DSSCs show an efficiency of 6.96% at a light intensity of 85 mW cm−2. The long‐term stability test reveals that the fabricated DSSCs will be stable even after 500 h. The benefits of incorporating a gel electrolyte into DSSCs are highlighted along with factors affecting the stability of these devices. The use of these bio‐based materials has the potential to make a significant contribution to the widespread exploitation of stable, efficient, and low‐cost dye‐sensitive solar cells.

Review on Functional Electrolyte, Redox Polymers, and Solar Conversions in 3G Emerging Photovoltaic Technologies: Progress and Outlook

“…The polar functional group grafted over dye acts as a bridging and anchoring group. 80,81 Sensitizer functional group acts as driving force which interacts with redox components of electrolyte for photovoltaic redox reaction 83…”

“…Sensitizer functional group acts as driving force which interacts with redox components of electrolyte for photovoltaic redox reaction normalΔ G r e g = E D y e ( H O M O ) − E r e d o x where Δ G reg refers to the change in Gibbs free energy for regeneration of oxidized dye with reducing components of electrolyte. Dye regeneration favors a higher redox potential (more negative) than the HOMO (dye) level.…”

“…Proper interaction is due to well matched energy levels between the dye and functional electrolyte. The more positive level of highest occupied molecular orbital (HOMO) of the dye than the redox potential of the electrolyte may inject photoexcited hole leads to the oxidation of the redox shuttle . Metalorganic ZIF-67 (complex containing Co ion and 2-methylimidazole) nanoparticles with noncoordinated cobalt ions allowed tuning of the optical properties, including the light absorbance, color and trigger a binary redox couple reaction which develops functionalized energy level for high efficiency DSSCs .…”

“…The more positive level of highest occupied molecular orbital (HOMO) of the dye than the redox potential of the electrolyte may inject photoexcited hole leads to the oxidation of the redox shuttle. 83 Metalorganic ZIF-67 (complex containing Co ion and 2methylimidazole) nanoparticles with noncoordinated cobalt ions allowed tuning of the optical properties, including the light absorbance, color and trigger a binary redox couple reaction which develops functionalized energy level for high efficiency DSSCs. 84 Poly(ethylene glycol)−hydroxyethylcellulose gel electrolyte has been reported for better interaction with indole-derived metal free dye containing an electronwithdrawing group.…”