Minimization of Photovoltage Loss of Iodine Electrolytes by Ethylene Carbonate and PAN-Based Block Copolymer for High-Performance Quasi-Solid-State Organic Dye-Sensitized Solar Cells

Herein, quasi-solid-state organic dye-sensitized solar cells with photovoltage around 830 mV under 1-sun and 720 mV under 1000 lx CFL ambient light were reported for iodide/triiodide redox shuttles by PAN-b-PEO-b-PAN (PAN = polyacrylonitrile, PEO = poly(ethylene oxide)) block copolymer (BCP) matrix and ethylene carbonate (EC) plasticizer. The photovoltages obtained here are comparable to our previously reported photovoltage for cobalt electrolyte devices. The negligible loss of photovoltage for iodine electrolytes can be attributed to the significant minimization of charge recombination due to the interaction of triiodide ions with EC-plasticized PAN-based BCP. The fabricated devices were stable under 30 °C and ambient conditions without photovoltage loss, which is a common characteristic of acetonitrile-based iodine electrolyte devices. This study also infers that the reversible addition-fragmentation chain transfer (RAFT)-synthesized trithiocarbonate-ended PAN-based BCP can be effectively utilized as a matrix for iodine liquid electrolytes.