Technical Insight
Rare earth ions change LED colors (Asia News)
Researchers at Osaka University have developed new technology that can adjust the color of light emitted from LEDs. According to a report in the Nikkei Business Daily, the LED is covered with transparent plastic containing rare earth complex ions. When light emitted by these ions is added to the light from the LED, the color of the overall light emitted is changed. For example, by covering an LED that emits white light with plastic containing europium ions, the result is red emission. Similar results were found with terbium (giving green light) and cerium (blue). Using the appropriate quantities of these three types of ions made it possible to minutely adjust the LED color.