Enhanced output power in an InGaN-GaN multiquantum-well light-emitting diode with an InGaN current-spreading layer

InGaN-GaN multiple quantum-well (MQW) light-emitting diodes (LEDs) with InG aN current-spreading layer were grown by metal-organic vapor-phase epitaxy (MOVPE) and their characteristics were evaluated by current-voltage (I - V) , as well as output power measurements. Experimental results indicate that the LEDs exhibited a higher output power and a lower operation voltage than that of conventional LEDs. The external quantum efficiency of InGaN-GaN MQ W LEDs for bare chips operated at injection current of 20 mA with InGaN cur rent spreading layer near 5%. This is two times higher than that of convent ional LEDs. This could be tentatively attributed to the better current-spre ading effect resulting from Si-doped In0.18Ga0.82N-wide potential well in w hich electron states are not quantized.