Perylenes are aromatic hydrocarbons with a fused ring system consisting of four benzene rings that exhibit strong luminescent and electron-accepting properties. They can be functionalized with various substituents to tune their electronic and optical properties, making them versatile building blocks for small-molecule semiconductors. In OLEDs, perylenes are luminescent materials with high quantum yields and good color purity. In OPVs, they can act as electron-accepting elements to improve the efficiency of photovoltaic cells. Their stable aromatic framework and excellent electronic properties make them attractive for use in high-performance organic electronic devices.