Multi-stack package led

摘要

A multi-stack package light emitting diode (LED) includes an LED chip, a first fluorescent powder layer, a first optical bandpass filter layer and a second fluorescent powder layer. The LED chip generates an LED light. The first fluorescent powder layer and the second fluorescent powder layer respectively have a first fluorescent powder and a second fluorescent powder. The first fluorescent powder and the second fluorescent powder are excited by the LED light to respectively generate a first excitation light and a second excitation light. The first optical bandpass filter layer allows the LED light and the first excitation light to pass and reflects the second excitation light. A wavelength of the LED light is shorter than a wavelength of the second excitation light. The wavelength of the second excitation light is shorter than a wavelength of the first excitation light. Therefore, the multi-stack package LED improves a light emission efficiency.