Abstract
A new type of light-emitting diode (LED) has been developed, the light intensity of which is stable during temperature change. This device consists of a multilayer dielectric optical filter on the surface of a conventional LED. The transmissivity of the optical filter is low for the short wavelength region of the LED's light spectrum and high for the long wavelength region. When the LED's temperature increases, the spectrum of LED light shifts toward the long wavelength side because of the shrinkage of the energy gap of the compound semiconductor. The shift increases the total transmission of the light because the transmissivity is high for the long wavelength region. This increase compensates for the decrease of the LED light intensity, which is caused by the decrease of the internal quantum efficiency. The effect of this filter is confirmed by both calculation and experiment.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.