Quest and designing of organic molecular frameworks for efficient hole transport materials

Azaborine derivatives were investigated as hole-transporting materials (HTMs) by employing density functional theory (DFT) calculations. Marcus theory and Einstein relationship have also been used to investigate different properties of HTMs. We have also performed time-dependant density functional theory (TD-DFT) calculations to investigate the optical, electronic and charge transport properties of designed molecules. Calculated results infer that the designed molecules display characteristic traits of a HTM. The calculated highest occupied molecular orbital (HOMO) level and hole reorganization energies are lower than that of electronic ones. Further, molecular electrostatic potential analysis and density of states are used to identify the various charge locations in molecules. To check the viability of our designed HTMs, we have taken 9:PC61BM complex for better understanding the charge transfer between the hole transport materials with well-known electron acceptor material. The designed hole transport materials based on azaborine were reported for perovskite solar cell that exhibit following characteristics: ➢ High hole mobility➢ Deep highest occupied molecular orbital level➢ Hole reorganization energies are lower than that of electronic ones➢ High open-circuit voltage. • Designed molecule display deep highest occupied molecular orbitals (HOMO). • Designed HTMs display hole reorganization energies which are lower than that of electronic ones. • The hole mobility of 2 and 5 shows highest hole mobility which is 4.56 and 4 ​× ​10 −2 in cm 2 v −1 s −1 respectively. • Designed HTMs ( 1 – 9 ) have stokes shifts between 64.41 and 72.04 ​nm. • The highest open circuit voltages are 1.69 and 1.12 shown by 7 and 9.