Copper selenide explained

Copper selenide is an inorganic binary compound between copper and selenium. The chemical formula depends on the ratio between the two elements, such as CuSe or Cu₂Se.

The crystalline structure and electronic behavior is determined by its elemental composition.^[1] Stoichiometric copper selenide is a zero bandgap material with metal-like behavior.^[2] Copper-deficient Cu_2-xSe (non-stoichiometric) is an intrinsic p-type semiconductor with direct and indirect bandgap energies in the range of 2.1–2.3 eV and 1.2–1.4 eV, respectively.^[3] It is frequently grown as nanoparticles or other nanostructures.^{[4] [5] [6]}

Uses

Copper selenide is produced in situ to form a protective black coating on iron or steel parts in some cold-bluing processes.^[7] Bluing solutions that operate in this manner will typically be labeled as containing selenous acid or selenium dioxide.^{[8] [9]} It has also been investigated for use in the treatment of colon cancer.

Natural occurrences

Copper selenides are the most common selenium minerals. CuSe is known in mineralogy as klockmannite,^[10] while Cu₂Se occurs as two polymorphs, berzelianite^[11] (isometric, more common) and bellidoite (tetragonal). There are more natural Cu selenides to date, including umangite, Cu₃Se₂ and athabascaite, Cu₅Se₄.^[12]

See also

• Gallium selenide
• Indium selenide
• Copper indium gallium selenide
• Copper sulfate
• Selenium dioxide
• Selenous acid

References

1. Lanling . Zhao . Wang . Xiaolin . F. Yun . Frank . The Effects of Te2− and I− Substitutions on the Electronic Structures, Thermoelectric Performance, and Hardness in Melt-Quenched Highly Dense Cu2-xSe . Advanced Electronic Materials . 5 February 2015 . 1 . 3 . 10.1002/aelm.201400015 . 137099918 . 28 June 2021.
2. Tyagi . Kriti . Gahtori . Bhasker . Enhanced thermoelectric performance of spark plasma sintered copper-deficient nanostructured copper selenide . Journal of Physics and Chemistry of Solids . June 2015 . 81 . 100–105 . 10.1016/j.jpcs.2015.01.018 . 2015JPCS...81..100T .
3. C. Singh . Subhash . Structural and compositional control in copper selenide nanocrystals for light-induced self-repairable electrodes . Nano Energy . September 2018 . 51 . 774–785 . 10.1016/j.nanoen.2018.07.020 . 30177955 . 6100260 .
4. Xiao. Guanjun. Ning. Jiajia. Liu. Zhaoyang. Sui. Yongming. Wang. Yingnan. Dong. Qingfeng. Tian. Wenjing. Liu. Bingbing. Zou. Guangtian. Solution synthesis of copper selenide nanocrystals and their electrical transport properties. CrystEngComm. en. 14. 6. 2139. 10.1039/c2ce06270d. 2012.
5. Hessel. Colin M.. Pattani. Varun P.. Rasch. Michael. Panthani. Matthew G.. Koo. Bonil. Tunnell. James W.. Korgel. Brian A.. 2011-05-10. Copper Selenide Nanocrystals for Photothermal Therapy. Nano Letters. EN. 11. 6. 2560–2566. 10.1021/nl201400z. 3111000. 21553924. 2011NanoL..11.2560H .
6. Patidar. D.. Saxena. N. S.. 2012-03-15. Characterization of single phase copper selenide nanoparticles and their growth mechanism. Journal of Crystal Growth. 343. 1. 68–72. 10.1016/j.jcrysgro.2012.01.026. 2012JCrGr.343...68P .
7. Web site: Room Temperature Black Oxide. 12 April 2016. 28 April 2016. https://web.archive.org/web/20160428155615/http://epi.com/c/black-oxide/steel/room-temperature-black-oxide. dead.
8. Web site: Insta-Blak 333 MSDS. 12 April 2016. https://web.archive.org/web/20160423045720/http://mobile.epi.com/doc/black-oxide/Insta-Blak-333-MSDS.pdf. 23 April 2016. dead.
9. Web site: Oxpho-Blue MSDS. 12 April 2016.
10. The crystal structure of covellite, cuse and klockmannite, cuse . Berry. L. G. . 1954. 39. 5–6 . American Mineralogist . 504–509.
11. An occurrence of a sulphur-bearing berzelianite . Harris . D. C. . Cabri . L. J. . Murray . E. J.. 1970 . The Canadian Mineralogist . 737–740.
12. Harris . D. C. . Cabri . L. J. . Kaiman . S.. 1970 . Athabascaite: A New Copper Selenide Mineral from Martin Lake, Saskatchewan . The Canadian Mineralogist . 10 . 2 . 207–215.