1) Zinc compound 
Zinc selenide (ZnSe), is a light yellow solid compound. It is an intrinsic semiconductor with a band gap of about 2.70 eV at 25 °C. ZnSe rarely occurs in nature. It is found in the mineral stilleite named after Hans Stille. ==Properties== ZnSe can be made in both hexagonal (wurtzite) and cubic (zincblende) crystal structure. It is a wide-bandgap ...
(from the article `spectroscopy`) ...near-infrared region either a quartz plate or silicon deposited on a quartz plate is used. In the mid-infrared region a variety of optical-grade ...
ZnSe Molar mass: 144.369