Phenothiazine based organic dyes for dye sensitized solar cells: A theoretical study on the role of π-spacer

In this contribution, six new organic dyes were investigated by the density functional theory (DFT). The electron-donor unit is a phenothiazine fragment substituted by an ethynyl-pyrene unit while the electron acceptor group is the cyanoacrylic acid for all sensitizers; the π-linker was changed and its effect investigated. The dye baring dioxythiophene linker has the highest absorption maxima. The theoretical photovoltaic properties indicated that the over-all yield of the solar cell could be remarkably improved with the designed dyes. The results showed that all the studied organic dyes are potential candidates as photosensitizers for dye sensitized solar cells (DSSCs).