Phosphor-converted light-emitting diodes (LEDs) were fabricated by precoating blue/green/red phosphors onto near ultraviolate (n-UV) LED chips prior to package into LED lamps. With a 20-mA injection current, it was found that the color temperature Tc was around 5900 K and the color-rendering index Ra was around 75 for the "n-UV+blue/green/red" white LED lamps. It was also found that no changes in color temperature Tc color-rendering index Ra could be observed when we increased the injection from 20 to 60 mA. These results indicate that such "n-UV+blue/green/red" white LEDs are much more optically stable than the conventional "blue+yellow" LEDs.
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