Indium(III) phosphide is widely used in optoelectronic devices due to its direct bandgap and high electron mobility. It serves as a key material in the production of infrared light-emitting diodes (LEDs) and laser diodes, especially in fiber optic communication systems operating in the 1300–1550 nm range. It is also employed in high-efficiency solar cells, particularly in multi-junction photovoltaic cells used in space and concentrated photovoltaic applications. Additionally, it functions as a substrate or active layer in high-speed electronic devices such as heterojunction bipolar transistors (HBTs) and integrated circuits for microwave and millimeter-wave applications. Its compatibility with other III-V semiconductors makes it valuable in advanced semiconductor heterostructures.