Zinc Selenide (ZnSe) is a medium refractive index material (2.4@10nm) with good long wavelength transmission in the infrared and is widely used in infrared components, windows and lenses, and spectral ATR prisms. Alfa Chemistry can use ZnSe materials to custom fabricate optical components of virtually any shape and size to customer requirements. If you need help, please contact us.
Advantages and Uses of Zinc Selenide Materials
ZnSe materials are microcrystalline in structure, controlling grain size to produce maximum strength. Although single-crystal ZnSe is rare and not widely available, it is said to have lower absorption and is hence more useful for CO2 optics. At 300 ℃, znSe begins to severely oxidize; at 500 ℃, plastic deformation occurs; and at 700 ℃, dissociation occurs. ZnSe windows shouldn't be used above 250 ℃ in typical atmospheres for safety reasons.
Fig 1. FT-IR spectrum of ZnSe sample. (Senthilkumar K, et al. 2012)
The ZnSe material is suited for use as a reflector and focusing lens for high-power CO2 lasers because it has an ultra-wide transmission range, a high refractive index, and low infrared absorption. It is a popular material option for transmission examination of watery materials since it is insoluble in water. Additionally, ZnSe is frequently employed as a beam splitter and window for portable IR spectrometers since it is a comparatively tough and long-lasting material, especially when compared to potassium bromide (KBr).
Fig 2. Absorption spectra of ZnSe Sample. (Senthilkumar K, et al. 2012)
ZnSe has an excellent spectral range coverage and wear resistance, making it a popular material for attenuated total reflection (ATR) studies. The majority of military uses, including thermal imaging, have replaced germanium because it has no free carrier absorption at high temperatures. In extremely powerful laser systems, as those utilized in laser processing, ZnSe is also employed.
Advantages:
- Zero water solubility
- good chemical resistance
- Most popular ATR spectroscopy materials
- Good spectral range window down to 500 cm-1 and beamsplitter down to 600 cm-1
- High index of refraction allows design of excellent broadband anti-reflection (BBAR) coatings
Properties of Zinc Selenide Materials
| Density | 5.27 g/cc |
| Molecular Weight | 144.33 |
| Solubility | 0.001g/100g water |
| Class/Structure | HIP polycrystalline cubic, ZnS, F43m |
| Melting Point | 1525 ℃ |
| Hardness | Knoop 120 with 50g indenter |
| Refractive Index | 2.4028 at 10.6 μm |
| Transmission Range | 0.6 ~ 21.0 μm |
| Reflection Loss | 29.1% at 10.6 μm |
| Reststrahlen Peak | 45.7 μm |
| Absorption Coefficient | 0.0005 cm-1 at 10.6 μm |
| dn/dT | 61x10-6/℃ at 10.6 μm at 298K |
| Youngs Modulus (E) | 67.2 GPa |
| Bulk Modulus (K) | 40 GPa |
| Thermal Expansion | 7.1x10-6/℃ at 273K |
| Thermal Conductivity | 18 W/m/K at 298K |
| Specific Heat Capacity | 339 J Kg-1 K-1 |
| Poisson Ratio | 0.28 |
| Apparent Elastic Limit | 55.1 MPa (8000 psi) |
About refractive index parameters.
"No" means ordinary light.
| µm | No | µm | No | µm | No |
|---|---|---|---|---|---|
| 0.54 | 2.6754 | 0.58 | 2.6312 | 0.62 | 2.5994 |
| 0.66 | 2.5755 | 0.7 | 2.5568 | 0.74 | 2.5418 |
| 0.78 | 2.5295 | 0.82 | 2.5193 | 0.86 | 2.5107 |
| 0.90 | 2.5034 | 0.94 | 2.4971 | 0.98 | 2.4916 |
| 1.0 | 2.4892 | 1.4 | 2.4609 | 1.8 | 2.4496 |
| 2.2 | 2.4437 | 2.6 | 2.4401 | 3.0 | 2.4376 |
| 3.4 | 2.4356 | 3.8 | 2.4339 | 4.2 | 2.4324 |
| 4.6 | 2.4309 | 5 | 2.4295 | 5.4 | 2.4281 |
| 5.8 | 2.4266 | 6.2 | 2.4251 | 6.6 | 2.4235 |
| 7 | 2.4218 | 7.4 | 2.4201 | 7.8 | 2.4183 |
| 8.2 | 2.4163 | 8.6 | 2.4143 | 9.0 | 2.4122 |
| 9.4 | 2.4100 | 9.8 | 2.4077 | 10.2 | 2.4053 |
| 10.6 | 2.4028 | 11 | 2.4001 | 11.4 | 2.3974 |
| 11.8 | 2.3945 | 12.2 | 2.3915 | 12.6 | 2.3883 |
| 13.0 | 2.3850 | 13.4 | 2.3816 | 13.8 | 2.3781 |
| 14.2 | 2.3744 | 14.6 | 2.3705 | 15.0 | 2.3665 |
| 15.4 | 2.3623 | 15.8 | 2.3579 | 16.2 | 2.3534 |
| 16.6 | 2.3487 | 17 | 2.3438 | 17.4 | 2.3387 |
| 17.8 | 2.3333 | 18.2 | 2.3278 |
Reference
- Senthilkumar K, et al. (2012). "Synthesis and Characterization Studies of ZnSe Quantum Dots." Journal of Materials Science: Materials in Electronics. 23(11): 2048-2052.