Can B─N Isosteres Utilize for the Designing of New Organic Hole Transport Materials? A Theoretical Prospective

Abstract Perovskite solar cells (PSCs) have attracted considerable attention from scientists due to their photophysical characteristics, cost‐effective manufacturing and impressive power conversion efficiencies. Hole transport materials (HTMs) are pivotal in improving the power conversion efficiencies (PCEs) and extending the diffusion length of holes and electrons within PSCs. Within hole transport materials, the alteration of π‐linkers has demonstrated to be a productive method for boosting the overall PCE of PSCs. In the current study, a series of hole transport materials were designed by utilizing the B─N substituted π‐linkers. The structural, optical, charge transport and electronic characteristics of these HTMs were analyzed employing density functional theory (DFT), time‐dependent density functional theory (TD‐DFT) and subsequently compared with a reference molecule. Among the HTMs that have been designed, HTM 9 stands out due to its promising characteristics: a narrow band gap of 2.155 eV, higher hole mobility at 3.166 × 10 −2 cm 2 v −1 s −1 and the designed HTMs ( 1–9 ) exhibit reorganization energy values for hole and electron that are considered favorable. These findings indicate that these designed molecules are efficient for use as hole transport materials in perovskite solar cells. Additionally, various analyses such as transition density matrix (TDM), density of states (DOS), partial density of states (PDOS) and molecular electrostatic potential (MEP) have been conducted to identify the different charge sites within the molecules.