Porphyrin dyes bearing heterocyclic anchoring groups for dye-sensitized solar cells with enhanced efficiency and long-term stability: Further optimization of champion porphyrin dye SM315

Abstract

In order to further enhance the long-term stability of porphyrin-based dye- sensitized solar cells (DSSCs) without losing their high efficiency, a serious of porphyrin sensitizers based on the champion dye SM315 but differing in the anchoring groups were theoretically investigated. Compared with SM315 with carboxylic acid anchoring groups, our results demonstrate that porphyrin dyes with hydantoin and barbituric acid anchoring groups exhibit stronger adsorption stability because of the larger orbital interactions between the dye and the semiconductor surface, according to the energy decomposition analysis. Furthermore, porphyrin dyes with these two heterocyclic anchoring groups can also display a superior or comparable charge separation and injection, light harvesting ability and conduction band energy shift, which are the key factors that affect the performance of DSSCs. These results highlight the great potential hydantoin and barbituric acid anchoring groups possess as effective alternatives to carboxylic acid anchoring groups for porphyrin dyes, which could yield an enhanced efficiency and long-term stability and worthy of being experimentally synthesized.