PAN-Based Triblock Copolymers Tailor-Made by Reversible Addition–Fragmentation Chain Transfer Polymerization for High-Performance Quasi-Solid State Dye-Sensitized Solar Cells

Abstract

For efficient polymer gel electrolytes (PGEs) in quasi-solid-state dye-sensitized solar cells (QSS-DSSCs), six ABA triblock copolymers based on (poly­(acrylonitrile-co-N-(isobutoxymethyl)­acrylamide)-block-poly­(ethylene glycol)-poly­(acrylonitrile-co-N-(isobuto-xymethyl)­acrylamide)) (P­(AN-co-BMAAm)-b-PEG-b-P­(AN-co-BMAAm)) with various copolymer compositions and molecular weights, coded as SGT-605, SGT-606, SGT-608, SGT-609, SGT-611, and SGT-612, have been synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization using PEG-functionalized macro-RAFT agents. The effects of copolymer compositions and molecular weights in P­(AN-co-BMAAm)-b-PEG-b-P­(AN-co-BMAAm) triblock copolymers were investigated in terms of electrochemical properties and photovoltaic performance as PGEs. The ionic conductivity was increased with N-(isobutoxymethyl)­acrylamide (BMAAm) composition of these triblock copolymers, which is attributed to the availability of free iodide ions by complex formation among acrylamide groups with Li+ ions. However, polymer gel electrolytes with high molecular weights enhance ionic conductivity due to the lower amount of polymers required for the gel formation. Thus, the photovoltaic performances of PGE-based QSS-DSSCs improved along with the increase in the molecular weight of the triblock copolymer. The addition of 7 wt % TiO2 nanofiller into PGEs produced a higher ionic conductivity and diffusion of I3 – than the corresponding PGEs. The resulting power conversion efficiency (PCE) of QSS-DSSCs using SGT-612/TiO2 composite PGEs under simulated 1-sun condition was 9.83% (V oc, 792.8 mV; J sc, 16.65 mA/cm2; FF, 74.52%), which was higher than that of liquid electrolyte DSSCs (PCE 9.53%; V oc, 743.8 mV; J sc, 17.16 mA/cm2; FF, 74.64%). The long-term device stability of PGE-based QSS-DSSCs was better than the liquid-state DSSCs.

High‐Voltage Quasi‐Solid‐State Dye‐Sensitized Solar Cells Based on Copper Redox Shuttles

“…a) J − V curves measured under 100 mW cm −2 (AM 1.5G) illumination, b) IPCE and c) J sc and V oc variation against light intensity of three quasi‐solid‐state DSSCs. d) V oc and PCE of quasi‐solid‐state DSSCs in our work and previously‐reported works (blue triangle represented the result of C‐EP cell with copper redox shuttles, red square represented those from the cobalt redox shuttles, [ 27–30 ] brown circle represented those from iodine redox shuttles [ 31–33,11c,12a,b ] ).…”

Dye-sensitized solar cells strike back

“…They can infiltrate and create a contact with the photoanode very effectively in order to ensure fast dye regeneration and, at the same time, possess high conductivity, which leads to quick transport of charges towards the counter electrode. 333,338,412,[414][415][416][417][418][419][420] Polyacrylonitrile (PAN), poly(ethylene oxide) (PEO) derivatives, conducting polymers including polypyrrole (PPy), polyaniline (PAni) and other polymers are the typical host materials (Fig. 35).…”

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

“…Efficient charge transfer requires compatibility between Fermi level of (TiO 2 ) and electrolyte potential . Electrolyte additive bind electrolyte cations thereby, increasing the electrical conductivity of the redox-active couple. , The extended block copolymer favors the production of a freely available electrolyte anion. The grafting of side chains and substitution of the carbon atom with nonmetal (N, F, and O) both have positive impacts on the energy levels of a polymer.…”