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Natnael Masresha Zerihun

LED Phosphor Aging: Measurement Methods and Degradation (Review)

Project Laboratory, BME Department of Electron Devices · Budapest, Hungary · Autumn 2025 · Academic project · Individual, supervised

A supervised literature study at BME on how wavelength-converting phosphors in white LEDs age, and how that aging is measured, synthesizing more than 20 studies into a technology comparison.

  • LEDs
  • Phosphors
  • Reliability
  • Literature review

Overview

This is a review, not experimental work: a structured survey of phosphor degradation mechanisms in phosphor-converted white LEDs, the measurement techniques used to quantify them, and how packaging choices change the outcome, with a bibliometric analysis and a technology-readiness comparison across encapsulation approaches.

Results

  • Synthesized findings such as silicone-YAG:Ce packages losing 7 to 12 percent flux after 500 hours at 150 C in the surveyed studies, versus under 3 percent for glass-ceramic converters
  • Compared measurement approaches (thermal, optical, spectral) across the surveyed literature in a structured comparison table