A study of silicon and germanium-based molecules in terms of solar cell devices performance

Photovoltaic energy sources are increasingly in demand due to the cost of petroleum fuels and concerns about carbon emissions. For this reason, it is important to determine the photovoltaic properties of the compounds that are thought to be suitable for these energy sources. Here, 1,1,2,3,4,5-Hexaphenyl-1H-silole (HPS) and 1,1,2,3,4,5-Hexaphenyl-1H-germole (HPG) compounds that are thought to have excellent photovoltaic properties, electronic and charge transport properties were investigated experimentally and theoretically. The total energies, absorption spectra, Fermi energy (E_fl) and work function (φ), maximum open circuit voltage (V_OC), reorganization energies (λ_e and λ_h), frontier molecular orbital (HOMO and LUMO), the ionization potentials (IPs) and electron affinities (EAs), effective transfer integrals (V_e and V_h), charge transfer rates (W_e and W_h), molecular electrostatic potential (MEP) surface analysis and Natural Bond Orbital (NBO) analysis were determined and the suitability of the results for photovoltaic solar cell devices was interpreted in detail. The absorbance spectra of the HPS and HPG were experimentally examined and compared to the theoretical results. It can be concluded that HPS and HPG would contribute to the application areas of more effective solar cells with determined properties.