Towards low cost and green photovoltaic devices: Using natural photosensitizers and MoS2/Graphene oxide composite counter electrodes

Photovoltaic systems, for example, dye-sensitized solar cells (DSSCs), are one of the useful tools for producing renewable and green energy. To develop DSSCs technology, it is necessary to overcome obstacles such as the need for expensive compounds. A series of DSSCs were designed and manufactured based on natural dyes extracted from cornelian cherry, black pomegranate, ruby grape, and tangerine peel as photosensitizers. The performance, structure, and interaction of the prepared extracts were evaluated by ultraviolet–visible spectroscopy, cyclic voltammetry, and Fourier transform infrared spectroscopy. Then, the prepared low-cost green dyes were employed in the preparation of DSSCs. A new MoS2/GO hybrid or composite was also employed instead of platinum. The synthesized MoS2/GO hybrid or composite was evaluated by field emission scanning electron microscopy and the results illustrated that the desired compound was synthesized successfully. Finally, DSSCs were prepared using MoS2/GO hybrid or composite and compared with that containing platinum. Under same conditions, the DSSCs with MoS2/GO composite illustrated better efficiency than MoS2/GO hybrid. The co-sensitization of Pt-free DSSC based on natural dyes has been studied for the first time in this work, which provides with expanding photovoltaic absorption range.