This preview shows page 1. Sign up to view the full content.
Unformatted text preview: ent diodes, which are also
known as LEDs (light emitting diode). For special applications, laser diodes are also
used. © Festo Didactic GmbH & Co. KG • FP 1110 189 11. Physical fundamentals For receiving elements, photodiodes or phototransistors are generally used. In
addition, photoresistors are also of some signficance, e.g. in photoelectric exposure
meters. Luminescent diodes Luminescent diodes (LED) are semiconductor diodes which emit light beams when
an electrical current passes through. Depending on the composition of the semiconductor material, light beams of varying wavelength are created, see Table 11.4.2. Material Colour Wave length [nm] Gallium arsenide infrared 950 Gallium aluminium arsenide infrared 880 Gallium aluminium arsenide red 660 Gallium arsenide phosphide red 660 Gallium arsenide phosphide red 635 Gallium arsenide phosphide yellow 590 Gallium phosphide green 565 Gallium nitride blue 480 Table 11.4.2: Typical materials and wavelengths of luminscent diodes Luminescent diodes in the infrared and red spectral range are mainly used in
sensors, because this produces good adaption t...
View Full Document
This note was uploaded on 11/01/2012 for the course CHEMICAL 102 taught by Professor Jamesrodriguez during the Spring '12 term at Universidad Politécnica de Cartagena.
- Spring '12