Theory study on the properties of thiadiazole polymer donors for organic solar cells

摘要

In this work, the properties of [1,2,5] thiadiazolo [3,4-c] pyridine -alt-cyclopenta [2,1-b:3,4-b′] dithiophene (PT-CDT) and [1,2,5] thiadiazolo [3,4-c] pyridine-6-carbonitrile-alt-cyclopenta [2,1-b:3,4-b′] dithiophene (PCNT-CDT) as donors were investigated by means of Density Functional Theory. The electronic properties and optical absorption properties were discussed, and hole-transfer properties of donors were studied by Marcus electron transfer theory. The results indicate that the linear structure of PCNT-CDT and PT-CDT is more stable than the spiral structure of PCNT-CDT and PT-CDT; the absorption peak in visible region of PCNT-CDT is stronger and wider, and the absorption spectrum is more matchable to solar spectrum than PT-CDT, while the maximum absorption wavelength of PCNT-CDT has an obvious red shift; the two designed materials show strong intramolecular and intermolecular charge transfer properties; PCNT-CDT owns a large open-circuit voltage and low reorganization energy, as well as high holemobility. Therefore, the newly designed PCNT-CDT can be a potential donor material of organic solar cell.