Poly(3-hexylthiophene)-CdSe Quantum Dot Bulk Heterojunction Solar Cells: The Influence of the Functional End-Group of the Polymer

摘要

The development of the field of solar cells has a large implication in solving the global energy crisis. Inorganic photovoltaics based on crystalline silicon have shown high efficiencies (up to 30%) but are too expensive, whereas polymer-based photovoltaics have a low cost, are lightweight, and can form flexible solar panels. Regioregular poly(3- hexylthiophene) (P3HT) is one of the well known conjugated polymers with hole mobilities as high as 0.6 cm~2 V~(-1) s~(-1) and good processability. Conjugated polymer-quantum dots are good bulk heterojunction solar cells, as CdSe quantum dots (QD) with an electron affinity in the range of 3.8-4.5 eV can act as electron acceptors when combined with P3HT. The dispersion of QDs in the matrix poses a greater challenge for an efficient charge transfer. To overcome this problem P3HT was functionalized with thiol groups to provide intimate contact between the polymer and the CdSe through covalent interactions.