Computational screening of 3,5-dicarbonitrilepyridine (DCP) core based eco-friendly solvent processed hole-transport materials for perovskite solar cells: A DFT and TD-DFT study

Perovskite solar cells (PSCs) provide a premier option for next-generation photovoltaic technologies, providing elevated power conversion efficiencies (PCEs) and economical production methods. Being reliant on toxic solvents, such as dichloromethane, for the application of hole transport materials (HTMs) presents considerable environmental and health issues, obstructing their sustainable advancement. This study presents an assembly of green solvent-processable (toluene) DCP (3,5-dicarbonitrilepyridine) based HTMs designated as DCPM1-DCPM8, facilitating the production of PSCs with less environmental impact by analyzing their electronic, optical, thermodynamic, and chemical reactivity parameters. Density functional theory (DFT) simulations are used to examine the links between structure and properties, emphasizing charge transport and photophysical properties. The findings indicate that the designed HTMs demonstrate excellent HOMO energy levels, facilitating effective hole extraction and transmission while sustaining competitive PCE. The absorption spectra encompass the UV–visible range, augmenting the light-harvesting efficiency of the PSCs. Thermodynamic stability is validated by assessing solvation free energies in ecologically friendly solvents, underscoring the compatibility of these HTMs with sustainable processing techniques. Chemical reactivity characteristics confirmed the materials' potential for efficient charge transport and reduced recombination losses. Moreover, the developed HTMs exhibit enhanced film uniformity and stability when utilized with green solvents, facilitating prolonged device operation in environmentally friendly solvents and maintaining compatibility with the perovskite active layer.