Theoretical study for tuning the HOMO level of the donor to increase the efficiency through open-circuit voltage of small molecule solar cells

• Published in: 2017 International Conference on Technological Advancements in Power and Energy ( TAP Energy) pp. 1 - 6
• Main Authors: Anjali, C M, Chinnusamy, Saravanan, Nath, B. Gayathri, Dathan, Swathy, Adwith, S, Shaikh, Nasrin I., Dangate, Milind S.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2017
• Subjects: Absorption; charge density difference; Density functional theory; Discrete Fourier transforms; energy; Energy states; Force; Organic conjugated polymers; Photonic band gap; Photovoltaic cells; Plastics; quantum study
• DOI: 10.1109/TAPENERGY.2017.8397205

Density Functional Theory (DFT), the method has been used for the approach of pre-synthesis of virtual screening of newly designed small molecules. The designed four small molecules have been done using the concept of 'Medium donor-vinylene-strong acceptor'. Malononitrile is flanked on the donor moiety of benzo[1,2-b:6,5-b']dithiophene-4,5-dione(BDTD) connected with vinyl linked benzothiadiazole (BTD) moiety studied with strong electron withdrawing groups (EWG) such as F, CN, and NO 2 onto the benzothiadiazole unit. DFT and TD-DFT method provided results of studied small molecules with 1.79eV-2.06eV band-gap with simulated high energy open-circuit voltage of 1.38V-1.49V for designed small molecules. The calculation also indicates D1, which exhibits the highest power conversion efficiency (∼9%) among the four systems predicted by Schraber diagram. This manuscript describes the detailed investigation of this study.