Temperature invariant energy value in LED spectra

Relativeemission spectra oflight-emitting diodes (LEDs) depend on thejunction temperature. The high-energy region of theemission spectrum can be modelled with Maxwell-Boltzmann distribution as a function ofenergy andjunction temperature. We show that according to the model and our experiments, the normalizedemission spectra at differentjunction temperatures intersect at a uniqueenergy value. The invariant intersectionenergy exists for many types of LEDs and can be used to determine the alloy composition of thematerial. Furthermore, the wavelength determined by the intersectionenergy can be used as a temperature invariant wavelength reference inspectral measurements.

Source: Applied Physics Letters - December 7, 2016 Category: Physics Authors: Hans Baumgartner, Anna Vaskuri, Petri K ärhä and Erkki Ikonen Source Type: research