Executive Summary : | Improving the color precision of display devices is a fascinating area of contemporary research across the globe and enhancement of the excited state lifetime is the key controlling step. In this context, reverse intersystem crossing guided delayed fluorescence already proved its efficacy in improving the precision of the emission wave length. However, Reverse intersystem crossing is an endothermic process and in a ground breaking experiment, it has been found that reverse intersystem crossing could be made barrier free in an optical cavity. The present project proposal is aimed at developing new theoretical method and computer program to elucidate a novel experimental findings, namely, barrier free reverse intersystem crossing in an optical cavity whose microscopic mechanism and full quantum dynamical theory to explain the observation is yet to develop. In this regard, polariton coupled cluster theory will be formulated after considering the strong coupling between the electronic and the photonic state state space. This Polariton coupled cluster method will be used in the next to develop the rate constant of reverse intersystem crossing between the lower polariton singlet and the first triplet state in the framework of time dependent correlation function based method. The formulation of the rate constant of the barrier free reverse intersystem crossing will be done after taking the angle between the transition dipole moment vector of the sâ state and the direction of the incident photon in the cavity into account. Fully MPI parallelized codes in F90 language will be written for both the methods which indeed would help us quantify the reverse intersystem crossing dynamics in optical cavity. A wide range of molecules that exhibit multi-resonant thermally activated delayed fluorescence will be considered in the present study, of course after benchmarking the existing experimental finding on molecular polaritons and the date available on barrier free reverse intersystem crossing dynamics. It is worth mentioning that the inversion of the singlet-triplet (sâ-Tâ) gap as observed in optical cavity also triggered interests to discover molecules with inherent inverted singlet-triplet(sâ-Tâ) energy gap that could be used for the next generation of display materials. This project will keep an eye on such molecular systems also and the comparison of the quantum efficiencies both the class of systems will be highly beneficial from the perspective of technological advances as well. Therefore the present project proposal will not only help us fine tuning our understanding of quantum dynamics involved with barrier free reverse intersystem crossing but also it has immediate societal impact. |