Role of novel carbon-oxygen-bridged Z-shaped non-fullerene acceptors for high efficiency organic solar cells.

The development of small molecule-based (SMs) organic photovoltaic (PV) materials is under intense attention by the researchers for organic solar cells (OSCs) to constantly revise their power conversion efficiencies (PCEs). Therefore, we have designed a series of Z-shaped non-fullerene acceptors (NFAs) (SNAA1-SNAA6), and characterized them theoretically for the possible use of in efficient OSCs devices. We have designed this Z-shaped series after employing several end-capped modifications over reference molecule (COi5DFIC (R)) to enhance their photovoltaic parameters further. We have extensively characterized these Z-shaped NFAs and explored their optoelectronic, photovoltaic and structure-property relationship with density functional theory (DFT) and time-dependent (TD-DFT). As a result, this Z-shaped NFA series (SNAA1-SNAA6) showed attractive narrower bandgaps (E g) compared to parent molecule R, and all are extremely red-shifted in the UV-Visible absorption spectrum. Moreover, we have also performed a complex study of donor:acceptor (D:A) blend (SNAA1:PTB7-Th) to show their compatibility in fabricating highly efficient OSCs devices. • Z-Shaped Non-fullerene acceptors (SNAA1-SNAA6) are designed for organic solar cells. • Highly red-shifted absorption, and an attractive narrow band-gaps are observed. • The non-fullerene acceptors showed an outstanding electron/hole reorganizational energy. • The designed materials (SNAA1-SNAA6) exhibited better optoelectronic properties as compared with reference R. [ABSTRACT FROM AUTHOR]