Theoretical investigation of thiophene-linked porphyrin-perylene photosensitiser for bulk-heterojunction solar cells

Abstract

In this work, quantum chemical calculations were applied to investigate a new series of porphyrin-perylene conjugates for their potential use as light-harvesting compounds in bulk-heterojunction solar cells. Molecular design relies on the integration of a electron-donating porphyrin and a electron-accepting perylene units via a spacer containing 0 to 10 thiophene rings. Electronic properties of these push–pull systems were studied using density functional theory (DFT) and time-dependent DFT approaches. Results show that introduction of thiophene-based spacer with different number of the thiophene rings significantly affects the electronic and absorption properties of the molecules. According to its suitable energy gap, efficient charge transfer and appropriate absorption behaviour determined by the calculation, the derivative having a terthiophene linker should be as the optimal compound among all molecules studied herein.

Keywords:

• Porphyrin
• perylene
• thiophene
• photosensitiser
• quantum chemical calculation

Acknowledgements

Authors would like to thank the Rachadapisek Sompoch Endowment Fund (2016), Chulalongkorn University (CU-59-044-EN). All facilities and computer was supported by Center of Excellence for Innovation in Chemistry, Office of the Higher Education Commission, Ministry of Education and Research and Development Institute Ramkhamhaeng University.