With the advancement of highly optimized photovoltaic devices, there is a pressing need for extensive strategies to drive further improvements in efficiency. Extensive research has focused on sub-wavelength structures with anti-reflection and light-trapping properties, though an optimal design remains elusive. This study explores the potential of artificial sub-wavelength optical structures, known as metamaterials, to address these challenges. Metamaterials, gaining attention for their perfect absorber capabilities, are integrated into solar cells to boost absorption and quantum efficiency. This paper highlights recent advancements in applying metamaterials to organic and perovskite solar cells, next-generation photovoltaic technologies, emphasizing their role in improving device performance and efficiency.