<title>High-brightness AlGaInP orange light-emitting diodes</title>

Orange AlGaInP high brightness light emitting diodes (LEDs) were fabricated by low pressure metalorganic chemical vapor deposition technology. AlGaInP double heterojunction structure was used as active layer. 15 pairs of Al_0.5Ga_0.5As/AlAs distributed Bragg reflector and 7 micrometers Al_0.8Ga_0.2As current spreading layer were employed to reduce the absorption of GaAs substrate and upper anode respectively. At 20 mA the LEDs emitting wavelength was between 600 - 610 nm with 18.3 nm FWHM, 0.45 mW radiation power and 1.7% external quantum efficiency. Brightness of the LED chips and LED lamps with 15 degree(s) viewing angle (2(theta) _1/2) reached 30 mcd and 1000 mcd respectively.