Temperature-Dependent Electroluminescence Efficiency in Blue InGaN–GaN Light-Emitting Diodes With Different Well Widths

Temperature dependence of electroluminescence (EL) efficiency in blue InGaN-GaN multiple-quantum-well (MQW) light-emitting diodes (LEDs) with different well widths is systematically investigated. The EL efficiency at 300 K shows a maximum at the input current of 4, 10, and 60 mA for the LEDs with 1.5-, 2.0-, and 2.5-nm QWs, respectively. Nevertheless, the droop behavior at 80 K is mainly dominated by the low hole mobility and near independence on the QW thickness. According to the simulation results, it is found that the distinct efficiency droop behavior for the LEDs with different well widths at high and low temperature is strongly dependent on the effects of electron overflow and nonuniform hole distribution within the MQW region.