Poly(3,4-ethylenedioxythiophene) Conjugated Polymer Quantum Dots as Photosensitizer for Quantum Dot Solar Cells

Abstract

Conductive polymers have been investigated as promising materials for electronics due to their unique optical and electrical properties since metal-insulator transition of iodine-doped polyacetylene was discovered in 1977. Poly(3,4-ehtylenedixoythiophene) (PEDOT), an inherently conductive conjugated polymer with high conductivity and excellent chemical stability, can be converted into polymer quantum dots showing size-dependent quantum confinement effect. PEDOT quantum dots (QDs) were successfully utilized as a photosensitizer for quantum dot sensitized solar cells (QDSCs) due to their adequate energy levels for charge transfer. They were prepared by a simple sonication method of nano-fibrous PEDOTs suspension, which were synthesized by oxidative chemical polymerization with a surfactant in N,N-dimethylmethanamide (DMF) solvent. The conjugated polymer quantum dots were heavy metal-free, environmentally friendly, stable and low cost, and were successfully utilized as a new class of photosensitizers for solar cells.