Ultraviolet-Visible Spectroscopy (UV-Vis-NIR)

Measurements in the ultraviolet/visible region (UV-VIS) cover wavelengths from about 200 nm to 800 nm. The absorption of ultraviolet or visible radiation by a molecule leads to transitions among the electronic energy levels of the molecule. It is ideal for characterizing the optical and electronic properties of various materials such as: films, powders, monolithic solids, and liquids.

The near-IR region (NIR) of the electromagnetic spectrum utilizes wavelengths from about 800-2500 nm. The transitions measured in this region are generally related to overtone and combination bands of mid-infrared vibrational modes.

Sample Requirements

  • Solids, liquids, and powders can be measured with relative ease
  • Sample size can vary from 2 x 2 mm up to several cm2
  • Contact the MCL staff analyst for additional information or to discuss your samples

User Policies, Procedures, and Training

Potential users are encouraged to contact the appropriate MCL staff member to discuss potential applications of this technique. If the technique is deemed appropriate, the user will be trained.

Instrumentation

Perkin-Elmer Lambda 950 UV-Vis-NIR Spectrophotometer

The Perkin-Elmer Lambda 950 is a high performance UV/Vis/NIR spectrophotometer capable of making measurements in the 190-3300 nm range. The extreme versatility of this instrument permits the acquisition of spectra from almost any type of sample. The current suite of sampling accessories permits acquisition of transmission (variable angle), diffuse transmission, specular reflectance (variable angle: absolute and relative), diffuse reflectance, and total reflectance spectra. A small spot focusing accessory permits analysis of samples as small as 2 mm x 2 mm without a significant decrease in S/N.

Details
  • Transmission
  • Specular Reflectance
  • Diffuse Reflectance
Sampling Accessories:
  • 150mm Integrating Sphere
    • small spot accessory (transmission, reflection)
    • diffuse reflectance (powders and monolithic solids)
    • variable angle transmission
  • Variable Angle Reflectance (automated, 6-68°)
  • Standard Transmission Detector
  • Polarization capabilities (210-3000 nm)