Amber InGaN-based light-emitting diodes operable at high ambient temperatures

High-efficiency amber InGaN single-quantum-well (SQW) structure light-emitting diodes (LEDs) with a luminous efficiency of 10 /m/W were developed. At a current of 20 mA, the external quantum efficiency, the output power and the emission wavelength of the amber InGaN SQW structure LEDs were 3.3%, 1.4 mW and 594 nm, respectively. The output power of InGaN LEDs was about twice as high as that of AlInGaP LEDs. There was a large difference in the temperature dependence of the output power between InGaN and AlInGaP LEDs. When the ambient temperature was increased from room temperature to 80 degrees C, the output power of AlInGaP LEDs decreased dramatically. On the other hand, the output power of the InGaN LEDs remained almost constant.