Amber Full Conversion Ceramics for LED Applications

Monochromatic amber light-emitting diodes (LEDs) have been widely adopted in the industrial and automotive applications. Although relatively efficient in room temperature, efficacy of direct AlGaInP amber LEDs suffers at higher application temperatures. The phosphor-converted LEDs overcome this drawback by generating amber light from all-nitride ceramic phosphor excited by an efficient blue InGaN chip. At room temperature and 700 mA drive current, the LED using such technique achieves a typical brightness of 135 lm. At application temperatures of 85 °C (Tj in the chip), the LED still achieves the impressive figure of 123 lm. In this talk, the effects of composition, phases and microstructure of (Sr,Ba)₂Si₅N₈:Eu full conversion ceramic phosphors on the color binning,  efficacy, thermal quenching and lifetime of phosphor-converted amber LEDs are discussed generally.