<p>➀ A nanostructured gold layer applied to ultrathin solar cells enhances light absorption by reflecting unabsorbed sunlight back into the cell, improving efficiency by ~1.5%;</p><p>➁ The gold layer, combined with an aluminum oxide coating, prevents electron loss and withstands high-temperature processing (450°C), maintaining stability; </p><p>➂ The nanoimprint lithography technique enables scalable production and compatibility with flexible materials, broadening applications in vehicles, buildings, and portable systems.</p>