Computational Analysis of Diverse Hole Transport Materials for Enhanced Efficiency in Perovskite Solar Cells

Hole transport materials stabilize and boost perovskite solar cell efficiency. In depth, understanding of the structure-property relationship will help in the rational design of efficient HTM for PSCs. In the present work, we have theoretically designed five efficient hole transport molecules based on triphenylamine as acceptor units. Their architecture is based on donor-acceptor-donor style using various core molecules e.g. thiophene, benzotrithiophene (BTT), benzo-2,1,3-thiadiazole (BT). Various p-linkers such as 3,4-ethylenedioxythiophene (EDOT), benzothiadiazole and thiophene are used for connecting both ends. Optical properties, electronic properties, hole transport behaviour, and photovoltaic properties are computed for the designed molecules based on DFT and TD-DFT methods on the basis of B3LYP hybrid functional. The geometries, ESP distribution, dipole moment, reorganization energies, UV-spectrum, and frontier molecular orbitals (FMOs) were discussed to study the electronic properties of the designed molecules. And the hole electron distribution, absorption spectra, Light harvesting Efficiency (LHE), alignment of the density of states along with transition density matrix, binding, and excitation energy were discussed to study the optical properties. This investigation provides an understanding of how the structure and properties of these molecules are related and how they can be modified to obtain desirable properties. This work will help design novel, efficient HTM molecules in the future by computational modelling and later leading to the fabrication of PSC devices with these types of HTMs.