Elucidating modelling of C≡N-based carbazole-arylamine hole transporting materials for efficient organic and perovskite solar cells

Abstract

Recently, the scientific community has shown great interest in hole transport materials (HTMs) to develop efficient and stable organic and perovskite solar cells. To boost the photovoltaic performance of these solar cell devices, scientists have been investigating the use of modified HTMs. In this study, we have developed a distinctive and proficient approach to building a better photovoltaic material by modifying the endcaps of the reference (MA). Specifically, we designed five new efficient HTMs (MA1-MA5) through molecular engineering on a terminal of reference molecule MA. Using density functional theory (DFT) and time-dependent-DFT methods, we theoretically characterized the key characteristics of these newly designed materials, including the orientation of frontier molecular orbitals (FMO), absorption maxima, the partial density of states (PDOS), binding energies, reorganization energy, transition density matrix, fill factor (FF), open-circuit voltages (Voc) and power conversion efficiencies (PCEs) for these materials. Our theoretical representations revealed that newly constructed materials (MA1-MA5) have a highly red-shifted absorption spectrum with lower binding energies and narrow energy gaps, making them ideal for charge shifting. Among these designed MA1-MA5 materials, the MA1 has the potential to produce as much as higher 23.24% PCE when it will be used in fabricating solar cell devices, whereas, the other designed materials MA2-MA4 has also very comparable and much higher PCE values than the refence molecule MA. These findings demonstrate our efficient designing approach to tune the photovoltaic and optoelectronic properties of the HTMs, and we recommend these engineered materials for the future developments of an efficient solar cell devices.