Exploiting the role of coadsorbents on photovoltaic performances of dye sensitized solar cells: A DFT study

Abstract

We examine the role of coadsorbents on dye-sensitized solar cells (DSSCs) with metal-containing and metal-free organic dyes to assess the performance computationally. The results corroborate well with the reported experimental results of Ru-containing dyes exhibiting that the co-adsorbent with longer alkyl chains anchored on the semiconductor surface lower the electron recombination process. The calculated results reveal that the co-adsorbents influence the conduction band energy level and that improve the effective density of states augmenting the forward electron transmission as well as reducing the electron recombination process. The role of co-adsorbents with metal-free organic dyes in DSSCs has also been examined. The computational results suggest that the metal-free organic dyes employed in DSSCs can achieve similar efficiency as reported with metal-organic sensitizers. The results revealed that co-adsorbents grafted through non-covalent interaction are more efficient in improving the efficiency of the DSSCs than co-adsorbents grafted through covalent bonds. The coadsorbents, 1-dimethoxyphosphoryloctadecane with long alkyl chains anchored on the semiconductor surface through hydrogen bonding interactions highly improve the effective density of states resulting in better forward electron transmission and may be one of the parameters to enhance the DSSCs efficiency.