Interface Engineering in Perylene Diimide-Based Organic Photovoltaics with Enhanced Photovoltage

• Published in: ACS applied materials & interfaces Vol. 15; no. 21; pp. 25224 - 25231
• Main Authors: Mohapatra, Aiswarya Abhisek, Pranav, Manasi, Yadav, Suraj, Gangadharappa, Chandrasekhar, Wu, Jiaying, Labanti, Chiara, Wolansky, Jakob, Benduhn, Johannes, Kim, Ji-Seon, Durrant, James, Patil, Satish
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 31.05.2023
• Subjects: cathodes; electric potential difference; polyethyleneimine; solar energy; nonfullerene acceptors; dipolar interaction; organic photovoltaics; perylene diimide; interface engineering
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.3c02003

The introduction of nonfullerene acceptors (NFA) facilitated the realization of high-efficiency organic solar cells (OSCs); however, OSCs suffer from relatively large losses in open-circuit voltage (V OC) as compared to inorganic or perovskite solar cells. Further enhancement in power conversion efficiency requires an increase in V OC. In this work, we take advantage of the high dipole moment of twisted perylene-diimide (TPDI) as a nonfullerene acceptor (NFA) to enhance the V OC of OSCs. In multiple bulk heterojunction solar cells incorporating TPDI with three polymer donors (PTB7-Th, PM6 and PBDB-T), we observed a V OC enhancement by modifying the cathode with a polyethylenimine (PEIE) interlayer. We show that the dipolar interaction between the TPDI NFA and PEIEenhanced by the general tendency of TPDI to form J-aggregatesplays a crucial role in reducing nonradiative voltage losses under a constant radiative limit of V OC. This is aided by comparative studies with PM6:Y6 bulk heterojunction solar cells. We hypothesize that incorporating NFAs with significant dipole moments is a feasible approach to improving the V OC of OSCs.