Solar cells need to convert more sunlight into energy efficiently. Scientists are using special materials like NaC s WO 3 and NaYF4 to improve solar cell performance. By adding these materials, they can change the sunlight's wavelength to match the solar cell's needs better. This helps increase the efficiency of solar cells, with some reaching up to 18.89% power conversion. By using these up-conversion nano-materials, scientists are making progress in creating more effective solar cells.