H2Se

Hydrogen selenide (H₂Se) is an inorganic compound that exists primarily as a gas at room temperature, though it can be studied in solid or crystallized forms in specialized research contexts. While classified here as a ceramic, H₂Se is more accurately a semiconductor precursor material valued in thin-film deposition and compound semiconductor manufacturing, where it serves as a chalcogen source for creating selenide-based optoelectronic and photovoltaic devices. Its primary engineering relevance lies in research and industrial fabrication of cadmium selenide (CdSe), zinc selenide (ZnSe), and other II–VI semiconductors used in infrared optics, photodetectors, and emerging solar cell technologies, though handling requires specialized equipment due to its toxicity and volatility.