Zinc Selenide - Applications

Applications

• ZnSe is used to form II-VI light-emitting diodes and diode lasers. It emits blue light.
• ZnSe doped with chromium (ZnSe:Cr) has been used as an infrared laser gain medium emitting at about 2.4 µm.
• It is used as an infrared optical material with a remarkably wide transmission wavelength range (0.45 µm to 21.5 µm). The refractive index is about 2.67 at 550 nm (green), and about 2.40 at 10.6 µm (LWIR). Similar to zinc sulfide, ZnSe is produced as microcrystalline sheets by synthesis from hydrogen selenide gas and zinc vapour. Lasertran (trademark of Rohm & Haas) grade is especially free of absorption and inclusions and is used particularly for CO₂ laser optics at 10.6 µm wavelength. It is thus a very important IR material. In daily life, it can be found as the entrance optic in the new range of "in-ear" clinical thermometers and can be just seen as a small yellow window. Zinc selenide can slowly react with atmospheric moisture if poorly polished, but this is not generally a serious problem. Except where optics are use in spectroscopy or at the brewster angle, antireflection or beamsplitting optical coatings are generally employed.
• ZnSe activated with tellurium (ZnSe(Te)) is a scintillator with emission peak at 640 nm, suitable for matching with photodiodes. It is used in x-ray and gamma ray detectors. ZnSe scintillators are significantly different from the ZnS ones.