Phenethylammonium lead iodide is primarily used in the development of perovskite solar cells, which are a promising technology for next-generation photovoltaic devices. Its application in solar cells is driven by its excellent light absorption properties and high charge carrier mobility, making it an efficient material for converting sunlight into electricity. Additionally, it is utilized in optoelectronic devices such as light-emitting diodes (LEDs) and photodetectors due to its tunable bandgap and strong photoluminescence. Researchers also explore its potential in creating flexible and lightweight electronic components, which could revolutionize wearable technology and portable electronics. Its ease of processing and low-cost fabrication further enhance its appeal in various advanced technological applications.