The growing world demand for sustainable and renewable forms of energy has led to increased research on enhancing the efficacy of photovoltaic (PV) cells. Of these methods, the use of nanomaterials has proven to be a breakthrough in solar cell technology. The unique optical, electrical, and structural characteristics of nanomaterials at the nanoscale provide superior light absorption, charge transport, and surface passivation. This article examines the function of different nanomaterials such as quantum dots, carbon nanotubes, graphene, and metal nanoparticles to enhance the efficiency of photovoltaic devices. By controlling their size, shape, and chemical composition, researchers have been able to optimize light-harvesting properties and reduce energy losses in PV cells. Moreover, the use of nanostructured layers has enhanced spectral response and operation stability of solar cells under varied environmental conditions. The review also touches upon the problems involved in large-scale production, long-term stability, and integration of nanomaterials into current photovoltaic technologies. The results indicate that nanomaterials have great potential for higher energy conversion efficiencies and the development of next-generation solar energy systems. Continuing research and development in this area may bring cheaper, more efficient, and longer-lasting photovoltaic solutions.