MOCVD Growth of High Output Power Ingan Multiple Quantum Well Light Emitting Diode

ABSTRACTThe MOCVD growth of InGaN / GaN multiple quantum well (MQW) structures for optoelectronic applications has been investigated. The structural and optical properties of the layers have been characterized by x-ray diffraction and photoluminescence. The effect of barrier and well dimensions on the optical properties have been examined; highest emission intensity and narrowest linewidth were obtained with thin wells (20–30 Å) and thick barriers (greater than 50 Å). By incorporating an MQW structure as the active region in a GaN p-n diode, high-brightness light emitting diodes (LEDs) have been produced. Under a forward current of 20 raA, these devices emit 2.2 mW of power corresponding to an external quantum efficiency of 4.5%. The emission spectrum peaks at 445 nm and exhibits a narrow linewidth of 28 nm. Under pulsed high current conditions, output power as high as 53 mW was realized and the peak emission wavelength shifted to 430 nm.