Copper (II) selenide is widely used in the field of semiconductor materials due to its favorable electronic and optical properties. It serves as a key component in the production of solar cells, where it acts as a light-absorbing layer, helping convert sunlight into electricity efficiently. The compound is also employed in thermoelectric devices, which convert heat directly into electrical energy, thanks to its ability to conduct electricity while maintaining low thermal conductivity.

In addition, copper (II) selenide is used in the development of photodetectors and sensors that respond to light and infrared radiation, making it useful in imaging and communication technologies. Its catalytic properties are leveraged in certain chemical reactions, including hydrogen evolution reactions in water splitting for clean energy applications.

Thin films of copper (II) selenide are applied in optoelectronic devices and as part of transparent conductive coatings. Ongoing research explores its potential in nanotechnology, particularly in nanoparticles for targeted drug delivery and medical imaging, due to its unique size-dependent properties and biocompatibility under controlled conditions.