This paper reports on an extensive analysis of the degradation of remote phosphors for solid-state lighting applications. The study is based on combined optical and thermal measurements, carried out before and during long-term stress tests, and provides the following results: 1) During normal operation, phosphors can show significant self-heating; 2) as a consequence of self-heating, the conversion efficiency of the phosphors decreases; and 3) exposure to long-term stress tests at moderate/high temperature levels (in the range of 85 °C-145 °C) can lead to remarkable degradation of the phosphors. Degradation mainly consists in a decrease in conversion efficiency and in worsening of the chromatic properties of the light-emitting diode-phosphor system. Finally, an activation energy value of 1.2 eV was extrapolated for the thermally activated degradation of the phosphors.

Thermally Activated Degradation of Remote Phosphors for Application in LED Lighting

MENEGHINI, MATTEO;DAL LAGO, MATTEO;TRIVELLIN, NICOLA;MENEGHESSO, GAUDENZIO;ZANONI, ENRICO
2013

Abstract

This paper reports on an extensive analysis of the degradation of remote phosphors for solid-state lighting applications. The study is based on combined optical and thermal measurements, carried out before and during long-term stress tests, and provides the following results: 1) During normal operation, phosphors can show significant self-heating; 2) as a consequence of self-heating, the conversion efficiency of the phosphors decreases; and 3) exposure to long-term stress tests at moderate/high temperature levels (in the range of 85 °C-145 °C) can lead to remarkable degradation of the phosphors. Degradation mainly consists in a decrease in conversion efficiency and in worsening of the chromatic properties of the light-emitting diode-phosphor system. Finally, an activation energy value of 1.2 eV was extrapolated for the thermally activated degradation of the phosphors.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2572833
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