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Junction temperature measurement of light emitting diode by electroluminescence
1Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan University, Hunan, Xiangtan 411105, China.
Abstract:
Junction temperature (JT) is a key parameter of the performance and lifetime of light emitting diodes (LEDs). In this paper, a mobile instrument system has been developed for the non-contact measurement of JTs of LED under LabVIEW control. The electroluminescence (EL) peak shift of the LED is explored to measure the JT. Commercially available high power blue LEDs are measured. A linear relation between emission peak shift and JT is found. The accuracy of the JT is about 1 °C determined by the precision of the emission peak shift, ±0.03 nm, at 3σ standard deviation for blue LED. Using this system, on-line temperature rise curves of LED lamps are determined.
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