Abstract
<jats:p>Singlet fission (SF) is a promising mechanism which can enhance the Shockley-Queisser limit of solar cell efficiency. In this work, we calculated the low-lying excited states of a star shaped molecule tetrathienylethylene (TTE) having slight two-dimensional extension and its substituted conformers mimicking the experiments in the singlet and triplet manifold which are crucial in understanding its photophysical properties. A slight two-dimensional extended geometry of TTE molecule is successfully handled and studied using the Density Matrix Renormalization Group (DMRG) technique within the Pariser-Parr-Pople model Hamiltonian. DMRG calculations on lowlying excited states show that relative energy ordering of the singlet and triplet states satisfies the required energy criteria for endoergic SF mechanism.</jats:p>