Scope of Utilizing Carotenoids for Enhanced Performance in Biohybrid Perovskite Solar Cells: A Computational Study

Abstract

Natural photosynthesis, driven by molecular machines that have continuously evolved over a long period, is the best-known efficient process of harvesting sunlight. Photosynthetic pigments in plants, algae, and cyanobacteria have remarkably higher quantum efficiencies than corresponding synthetic and semisynthetic materials used in photovoltaic cells. The antioxidative and intrinsic properties of natural pigments like carotenoids make them suitable for new-generation sustainable energy and green electronics applications. In this computational study, an attempt has been made to understand the scope of carotenoids as an additive to the active layer and/or eco-friendly alternatives to the hole transport materials (HTM) like Spiro-MeOTAD in preparing perovskite solar cells. Accordingly, quantum and moleculer mechanical simulations are done to evaluate and compare the optoelectronic parameters of some easily available carotenoids vis-à-vis some noncarotenoids like betacyanin, xylindein, and Spiro-MeOTAD. HOMO–LUMO energy levels of carotenoids aligned well with those of perovskite. In addition, their light absorption spectra are also found to be complementary, and hence, the carotenoids can exhibit tandem behavior in absorbing visible light along with perovskite materials. Hole reorganization energies (λ) of some carotenoids like capsorubin, capsanthin, and violaxanthin are almost equivalent to Spiro-MeOTAD's. Calculated glass transition temperatures (T_g) of carotenoids indicate their thermophysical stability during peak summer.