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LIGHT EMITTING DIODES:

•Solids can give off light when energized by application of electricity.

•The type of solid crystal used determines the wavelength of light given off.

•Light Emitting Diodes (LEDs) can generate red, yellow, green, and blue light.

•Scientists are working on a “white” LED that will produce incandescent light that is much more efficient than current lighting and will last much longer.

ATOMIC EMISSION SPECTROPHOTOMETER:

•Matter in gas form can also give off light when energized.

•The electronic structure of the gas determines the wavelengths of light given off and the overall color of light seen.

•An Atomic Emission Spectrophotometer (AES) is an instrument that can identify specific elements in a sample by comparing the spectrum of a known element to that of an unknown.

•AES can determine the identity of elements in a sample and the quantity of the element in the sample (the emission intensity at a characteristic wavelength of an element is nearly proportional to the concentration of an element in the sample).


PLASMA APPLICATION:

  • Plasma can be created during the emission process and can be used in various manufacturing processes.
  • A plasma is a gas that contains electrically charged particles—enough charged particles to significantly affect its electrical properties and behavior.
  • A plasma is created when gas atoms are “ionized” or broken into positively charged particles (positive ions) and negatively charged particles (electrons).
  • Although gaseous in nature, plasmas behave very differently form uncharged gases such as the air we breathe.
  • The method for creating plasma starts with the ionization process. Ions are typically created using high voltage.
  • The high voltage causes electrons in the atom’s outer energy level to be stripped away resulting in the formation of a positive ion.
  • The electrons accelerate through the low-density gas and collide with neutral atoms that create more unbounded electrons and positive ions.
  • Both are then accelerated in larger numbers. It is easier to create ions in a gas rather than in a liquid or solid due to its lower density.

MANUFACTURING PROCESSES:

Coating stainless steel equipment with a protective layer

Single-layer anti-reflective coatings

High durability “scratch resistant” coatings

Low friction films for coating the moving parts of complicated equipment

Transparent coatings for flat panel displays

Fiber optic coatings


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Spectroscopy – HSTI Educational Materials