Copper selenide

Copper selenide is a chemical compound with the formula Cu₂Se. It is a black crystalline solid that is insoluble in water. Copper selenide is a member of the family of copper chalcogenides, which are compounds formed between copper and chalcogen elements such as sulfur, selenium, and tellurium.

Structure

Copper selenide typically crystallizes in a cubic structure, similar to that of other copper chalcogenides. The structure consists of copper ions (Cu⁺) and selenide ions (Se²⁻) arranged in a lattice. The copper ions are often found in a distorted tetrahedral coordination with the selenide ions.

Properties

Copper selenide is known for its semiconducting properties. It has a narrow band gap, which makes it useful in various electronic and photovoltaic applications. The compound exhibits p-type conductivity due to the presence of copper vacancies in its structure.

Synthesis

Copper selenide can be synthesized through several methods, including:

• Direct combination of elemental copper and selenium at high temperatures.
• Chemical vapor deposition (CVD) techniques.
• Solution-based methods, such as the reaction of copper salts with selenide sources in a solvent.

Applications

Copper selenide is used in a variety of applications, including:

• Photovoltaics: As a component in thin-film solar cells, particularly in copper indium gallium selenide (CIGS) solar cells.
• Thermoelectric materials: Due to its semiconducting properties, it is used in thermoelectric devices that convert heat into electricity.
• Optoelectronics: In devices that require materials with specific electronic and optical properties.

Safety and Handling

Copper selenide should be handled with care, as selenium compounds can be toxic if ingested or inhaled. Proper safety equipment, such as gloves and masks, should be used when handling the material.

Also see

• Copper chalcogenide
• Selenium
• Semiconductor
• Photovoltaic cell
• Thermoelectric materials