Butylammonium lead iodide is primarily used in the development of perovskite solar cells, which are known for their high efficiency and cost-effectiveness in converting sunlight into electricity. Its application in these cells is crucial due to its excellent light absorption properties and ability to form high-quality perovskite films. Additionally, it is utilized in optoelectronic devices, such as light-emitting diodes (LEDs) and photodetectors, owing to its tunable bandgap and efficient charge carrier mobility. The compound also finds use in research focused on improving the stability and performance of perovskite-based materials for next-generation renewable energy technologies.