. In nanomaterials, the surface-to-volume ratio increases dramatically compared to macro-materials. It is said that nanomaterials have a very high surface area. Another expression of this statement is that the fraction of the number of surface atoms to the total number of atoms existing in a NP is close to 1, and in contrast for bulk materials this fraction is practically zero. This implies the great importance of the effect of surface atoms and surface-related properties in nanomaterials, while in macro-scale materials, , the effect of these atoms is ignored unless for describing surface properties. Because nanomaterials have a very high surface area, the use of a nanostructured layer of metal oxide semiconductor greatly increases the light harvesting, which eventually plays a decisive role in increasing the efficiency of the solar cell. Based on the literature review and among the many choices available from semiconductor materials, the best photodanodes in DSSCs are obtained from titanium dioxide anatase nanocrystals. In this research, considering the worldwide importance of clean energy topic, especially solar cell technology, and the useful and transformative role of nanomaterials in this subject, we aim to synthesize a composite layer consisting of magnesium ion-doped titanium dioxide nanorods and then use it in a DSSC, as one of the most important types of third generation solar cells.
