Enhanced Performance via π-Bridge Alteration in Phenothiazine-Based Novel Donors for Efficient Organic Photovoltaics

Abstract

Organic solar cells are promising low-cost energy conversion devices as a potential substitute for costly silicon-photovoltaics, but thermal degradation and lower photovoltaic properties of the organic materials severely affect their power conversion efficiency. To enhance their efficiency, we have introduced various π-bridges and acceptor groups to the reference molecule (PDO₂). In the present work five novel molecules, that is, M1–M5 were designed by substituting efficient π-bridges and end group acceptors to develop efficient hole transport materials for high performance organic solar cells. All molecules were optimized using the B3LYP functional at 6-31G (d, p) basis set for all the density functional theory (DFT) calculations. The results indicate significant improvements in the charge transfer, optical, electronic, geometrical, and photovoltaic properties of the newly designed molecules as compared to the reference molecule R. The open-circuit voltage of 0.91 V achieved for the M2 molecule. Other designed molecules also exhibited better optoelectronic and photovoltaic characteristics compared to the reference one. The reported photovoltaic parameters represent theoretical predictions based on DFT-derived electronic properties. The outcomes specify that the designed PDO₂ based donor molecules are promising hole transport materials for improving the performance of organic as well as perovskite solar cells.