Thin film electroluminescent displays (TFEL) work by exciting atoms with an electric current, causing them to emit photons of light. A TFEL is constructed with parallel electrode strips covered by an electroluminescent material layer, then a transparent electrode layer running perpendicularly. At each intersection of the electrodes, the material lights up as a pixel. TFEL displays have advantages like low power usage, long life, flexibility, and durability over a wide temperature range compared to LCDs. However, they also have disadvantages like low light output, reduced brightness over time, and need for high voltage.

1. Welcome
to our presentation

2. Topic:
Thin Film Electroluminescent Display

3. Thin Film Electroluminescent Display
Description :
Electroluminescence (EL) is an optical phenomenon and electrical
phenomenon in which a material emits light in response to the passage of
an electric current or to a strong electric field. This is distinct from black
body light emission resulting from heat (incandescence), from a chemical
reaction (chemiluminescence), sound (son luminescence), or other
mechanical action (mechanoluminescence).
Electroluminescence is the result of radiative recombination of electrons
and holes in a material .

4. Film Electroluminescent Display

5. Mechanism
EL works by exciting atoms by passing an electric current through them,
causing them to emit photons. By varying the material being excited, the
color of the light emitted can be changed.
The actual ELD is constructed using flat, opaque electrode strips running
parallel to each other, covered by a layer of

6. electroluminescent material, followed by another layer
of electrodes, running perpendicular to the bottom layer.
This top layer must be transparent in order to let light
escape. At each intersection, the material lights,
creating a pixel.

8. ADVANTAGE
• Low wattage.
• Long life.
• No external circuitry required.
• Can be manufactured into flat flexible panels, narrow strings, and other small
shapes.
• Can be made in water proof computer system which are more durable and
lightweight than LCDs and Plasma screens.
• Not directional like LCDs when used as a computer monitor, looks good at all.
• EL can handle impressive temperature -60C to 95C LCDs can’t do so.

9. Disadvantages
• Not practical for general lighting of large areas due to low lumen output
of phosphor so far.
• Poor lumen per watt rating, however typically the lamp is not uses for
high lumen output.
• Reduced lumen output over time, although newer technologies are
better than older phosphor on this point.
• Flexible flat EL sheets wear out as they get flexed, durability is being
worked on.
• The lamps can use significant amount of voltage (60-600 volt).
• Typically EL needs converter when used with DC source such as on
watches (to create higher frequency AC power, in this audible).

10. Reference
• [1.] https://en.wikipedia.org/wiki/Electroluminescent_display
• [2.] https://en.wikipedia.org/wiki/Electroluminescence
• [3.] https://beneq.com/en/displays/technology
• [4.] A. H. Kitai and F. Chan, “Thin film electroluminescence,” in
Handbook of Visual Display Technology, J. Chen, W. Cranton, and M.
Fihn, Eds. London, U.K.: Springer, 2012, ch. 6.5, pp. 1183–1192.