In silico designing of efficient C-shape non-fullerene acceptor molecules having quinoid structure with remarkable photovoltaic properties for high-performance organic solar cells

Non-fullerene acceptors (NFAs) are now under intense research to develop bulk-heterojunctions organic solar cells (OSCs). One fundamental approach to further improve the power conversion efficiency (PCE) of OSCs is to incorporate different end-capped units in a molecule. Herein, we efficiently designed a novel series of small molecule based non-fullerene acceptor molecules (CS1CS5) by doing end-capped modification of NTTI (reference molecule) for OSCs and characterized with density functional theory (DFT) and time-dependent (TD-DFT) quantum chemical calculations. Narrowing of HOMO-LUMO energy gap is noted in designed molecules (Eg=1.73-1.90 eV) as compared to reference molecule (Eg=1.91 eV). Red-shifting is also observed in absorption spectrum of designed molecules (lambda max=790-837 nm) as compared to R molecule (lambda max=786 nm). The characteristic electron and hole mobility, and open-circuit voltage (Voc) were also computed which suggested that designed molecules have good electron and hole mobility along fine values of fine values of open circuit voltage values (0.97-1.44 V). Further, low binding energies and excitation energies (Ex =1.48-1.58 eV) allows high charge transfer and maximum power conversion efficiency in designed molecules. The results revealed that all newly constructed SMsNFAs better exciton dissociation while, much lower LUMO energy levels which might facilitate to boost the reorganizational energies, open-circuit voltage, and photocurrent density values which will ultimately boosts the PCEs of the OSCs devices.

Automated summary

A novel series of small molecule based non-fullerene acceptor molecules were efficiently designed for organic solar cells (OSCs) by incorporating different end-capped units, showing improved power conversion efficiency. These designed molecules exhibited narrow HOMO-LUMO energy gap, red-shifted absorption spectrum, and good electron and hole mobility, leading to enhanced charge transfer and high power conversion efficiency. The results suggest that the newly constructed non-fullerene acceptor molecules have better exciton dissociation capabilities and lower LUMO energy levels, ultimately boosting the performance of OSC devices.